Latest: NATO Secretary-General Jens Stoltenberg says Russia should withdraw some 1,000 items of military equipment from Ukraine. He also said that any attempt by pro-Russian separatists to expand the territory they hold in eastern Ukraine would be "unacceptable."
More on the weapons withdrawal:
The Ukrainian military said it was starting to withdraw heavy weapons from the front line in its conflict with Russian-backed rebels on February 26 after reporting that there were no combat fatalities for a second straight 24-hour period.
The announcements raise hopes that a European-brokered cease-fire agreement reached in Minsk could be taking hold, after the rebels initially ignored the truce and seized the strategic town of Debaltseve in a major offensive.
"Implementing the agreements reached in Minsk on February 12, Ukraine is beginning the withdrawal of 100-mm guns from the line of
contact today," the military said in a statement. "This is the first step in the pull-back of heavy weapons."
Kyiv had been unwilling to begin its withdrawal because of what it said were persistent rebel attacks.
The conflict has killed more than 5,600 people in eastern Ukraine since April.
LATEST: Ukraine's military says it will begin withdrawing heavy weapons from the front line in eastern Ukraine on February 26.
Good news:
Ukraine's military has reported there were no combat fatalities in the conflict zone in the east for a second straight 24-hour period.
The February 26 announcement raises hopes the latest cease-fire agreement could be taking hold after Russian-backed separatists initially ignored the truce and seized the strategic town of Debaltseve in a major offensive.
National Security and Defense Council spokesman Andriy Lysenko said all conditions have now been created for government forces to withdraw their heavy weaponry from the front lines, a step Kyiv had been unwilling to take because of what it said were persistent rebel attacks.
The Council said the order to pull back heavy weapons had not yet been given, however.
At the devasted Donetsk airport -- the scene of some of the heaviest fighting in a conflict that has killed more than 5,600 people since April -- separatist forces claimed to have recovered the bodies of at least 30 Ukrainian soldiers.
Ukrainian troops were forced to abandon the airport last month.
More Russian military drills:
Russian fighter jets will take part in exercises on thwarting a potential attack over the Barents Sea, off the coasts of Russia and NATO member state Norway.
The Russian military said on February 26 that MiG-31 interceptor aircraft were taking part in the initial part of the exercises at an air base in the Perm region.
During the next stage, to be launched in the coming days from Monchegorsk air base in the northwestern region of Murmansk, crews will intercept missiles and planes of an imaginary army.
The drill is to end on March 6.
Russia's ex-Soviet neighbors in the Baltics and other NATO members have voiced concern over an increase in Russian air activity around Europe and a series of drills since the start of the conflict in Ukraine.
On February 25, Russian soldiers took part in drills in Pskov region bordering NATO and EU members Estonia and Latvia.
The drills, which will see some 1,500 paratroopers parachute en masse, were to continue until February 28.
Latest wrap from our news desk, leading with Lavrov's recent comments:
Russian Foreign Minister Sergei Lavrov lashed out at U.S. Secretary of State John Kerry and other Western officials on February 26 over threats to impose further sanctions against Moscow if it does not alter its conduct in Ukraine.
Lavrov said he believes talk of additional sanctions is meant to distract attention from the need to implement a deal on a cease-fire and steps toward peace in eastern Ukraine that was agreed on February 12 in Minsk.
He spoke after Kerry told U.S. lawmakers on February 25 that "neither Russia nor the forces it is supporting have come close to complying with their commitments" under the deal, which is aimed to end a war that has killed more than 5,600 people since April.
"As for the declarations by Western officials, including John Kerry and [European Council President] Donald Tusk, who have threatened new sanctions, I think this is easy to explain: They are trying to whip up hysteria and draw attention away from the need to implement the Minsk agreements," Lavrov told a news conference in Moscow.
He said such remarks reflected "a lack of desire" in "the United States and the EU to achieve what we agreed upon in Minsk on February 12."
Western officials say it is Moscow and the Russian-backed separatists holding parts of eastern Ukraine who have failed to implement the cease-fire.
Kerry accused Russian President Vladimir Putin of destabilizing Ukraine through "land grabs," and said: "We are poised yet to do another round [of sanctions] potentially, depending on what happens with [the cease-fire] in these next few days.
Immediately after the cease-fire was agreed, the rebels ignored it in order to continue an offensive and take the strategic town of Debaltseve, a rail junction between the separatist-held provincial capitals of Donetsk and Luhansk, from government forces.
Fighting has subsided since then, and the Ukrainian military said on February 25 that no deaths had been reported at the front for the first time since the cease-fire was to enter into force on February 15.
But there was still no confirmation from the Organization for Security and Cooperation in Europe (OSCE) of a pullback of heavy weapons from the front tline -- another key provision of the deal reached in Minsk.
Kyiv and Western governments believe Russia wants to weaken Ukraine and keep it out of NATO by maintaining a "frozen conflict" in the east for years to come.
They fear Putin and the rebels could push to seize a swath of territory stretching from Donetsk to Crimea, the Black Sea peninsula Moscow illegally annexed from Ukraine in March 2014.
Kerry told told the foreign affairs committee in the U.S. House of Representatives: "In Luhansk, and Donetsk, and now in Debaltseve, he [Putin] has empowered, encouraged, and facilitated directly land grabs in order to try to destabilize Ukraine itself."
He said that "if failure continues, there will be further consequences -- consequences that would place added strains on Russia's weakened economy."
French Foreign Minister Laurent Fabius also said on February 25 that Moscow would face more European Union sanctions if the separatists attack the Kyiv-controlled strategic port of Mariupol.
Top U.S. officials have lashed out at Putin and his ministers in recent days as the fighting has continued in Ukraine, with Kerry on Tuesday directly accusing Russian leaders of lying "to my face" over the conflict.
Asked if she believed Putin's assertions that he wanted peace in Ukraine, National Security Advisor Susan Rice retorted: "How dumb do I look?"
"No. In all seriousness, no. One cannot accept Vladimir Putin at his word because his actions have belied his words repeatedly, particularly in the context of Ukraine," Rice told PBS television.
On the ground in eastern Ukraine, the first day without fatalities was reported since the cease-fire came into effect on February 15.
"Over the past day, one soldier was wounded but there were no dead," Ukrainian military spokesman Andriy Lysenko told journalists in Kyiv. The rebels also reported no deaths on their side.
But the OSCE mission to Ukraine said it could still not confirm a pull-back of heavy weapons from the frontline.
Rebels have claimed they were withdrawing artillery, rocket launchers and tanks from some areas, and journalists saw a column of howitzer guns being driven along a road near the separatist stronghold of Donetsk.
OSCE monitors said the warring sides had not provided the information needed to determine what, if any, arms withdrawals have occurred.
Putin's spokesman, Dmitry Peskov, in an interview with CNN on February 25, accused OSCE monitors of "refusing" to observe the withdrawal of heavy weaponry by rebels in the Donetsk region.
But the head of the OSCE Parliamentary Assembly, Ilkka Kanerva said the separatists continued to impose restrictions on the monitors' movements.
Kanerva said in a statement that he was "profoundly disturbed" by the rebels' "continuing refusal to grant unlimited, safe access to OSCE monitors on the ground in Ukraine and their violations of the Minsk Package of Measures."
Ukraine has warned that it will not carry out an arms pull-back until a full and "comprehensive" cease-fire is observed and has accused Russia of continuing to send military hardware in to bolster the rebels.
Meanwhile, top U.S. defense leaders told Congress that the Obama administration is still debating whether to provide lethal defensive arms to Ukraine.
They expressed concern that such aid would only escalate Russia's military campaign there.
U.S. General Philip Breedlove, the top NATO commander, told the House Armed Services Committee that he has laid out military options the administration could consider for Ukraine, ranging from sending small arms to more sophisticated weapons that would take longer to arrive and require extensive training.
Breedlove and Christine Wormuth, defense undersecretary for policy, told lawmakers they are worried most that Russia might move on to destabilize non-NATO countries such as Montenegro or Moldova and expand its military assault into other portions of Ukraine.
Russia used troops and a referendum to seize control of Crimea after Ukrainian President Viktor Yanukovych fled Kyiv in February 2014 following months of huge protests over his decision to scrap plans for a landmark agreement with the European Union and tighten ties with Moscow instead.
In a sign of the damage the war has inflicted on Ukraine's economy, the central bank on February 25 imposed a temporary ban on purchases of foreign currencies, in an attempt to prop up the troubled hryvnya currency, which has lost some 70 percent of its value in the past year.
The ban should have been in effect from February 25 to February 27, but was reversed later in the day after criticism from Prime Minister Arseniy Yatsenyuk.
Good morning. Defense spending being cut in NATO countries:
A British-based think tank says some NATO member nations are cutting their spending on defense, despite stern talk and solemn pledges from the alliance.
In a report released February 26, the European Leadership Network said Britain, Bulgaria, Canada, Germany, Hungary and Italy are all on track to reduce military expenditures in 2015.
The report said that in France, spending is forecast to remain flat.
Ian Kearns, director of the European Leadership Network and the coauthor of the report said, "Despite Russian aggression in Ukraine and much rhetoric from NATO leaders that this has been a game-changer in European security, all the evidence suggests there is a continuation of business as usual."
In September, NATO leaders vowed to "reverse the trend of declining defense budgets."
The report found that six member nations -- Latvia, Lithuania, Netherlands, Norway, Poland and Romania -- will hike spending in 2015, but not reach the ultimate target of 2 percent of Gross Domestic Product agreed to at the NATO summit.
We are now closing the live blog for today. Until we resume again in the morning, you can follow all our Ukraine coverage here.