Carl Schreck followed up yesterday on the picture circulated on social media that could show Russian troops in Ukraine.
The latest on Zakharchenko's comments from our news desk:
The leader of pro-Russian separatists in eastern Ukraine's Donetsk region has said that rebel forces will seek to take over the entire province and will not intiate peace talks with goverment forces.
The remarks by the leader of the self-proclaimed People's Republic of Donetsk, Aleksandr Zakharchenko, further clouded prosects for peace following days of intensified fighting in a conflict that has killed more than 4,800 people since April.
"We will advance to the very borders of the Donetsk Oblast," the Russian news agency Interfax quoted Zakharchenko as telling students in the rebel-held provincial capital on January 23.
He added that "if I see a threat from other sides, we will liquidate it," Interfax reported.
"From our side, there will be no more attempts to talk about a truce," Zakharchenko said.
Latest from our news desk:
The United Nations says that at least 5,000 people have been killed in the conflict in eastern Ukraine since April and that the real figure may be "considerably higher."
UN human rights spokesman Rupert Colville said the toll incudes 262 people killed in the past nine days, making that "the most deadly" period since Ukraine and pro-Russian separatists agreed to a cease-fire on September 5.
Colville told a news briefing in Geneva on January 23 that a "significant escalation in hostilities has taken the toll to 5,086 individuals and we fear the real figure may be considerably higher."
BREAKING: Russian President Vladimir Putin says responsibility for the escalation of fighting in eastern Ukraine lies with those who issue criminal orders, wording Moscow has used in past to describe the Ukrainian government.
Slightly extended quotes from Aleksandr Zakharchenko, head of the self-proclaimed Donetsk People's Republic, speaking at a news conference today in Donetsk, via Reuters:
"There will be no cease-fire anymore. There will be no more rotations [for Ukrainian soldiers]. Yes we will exchange prisoners, I will explain why -- because our guys are there in captivity and we need to pull them out."
"Kyiv did not understand that we can be on the offensive from three directions at the same time. We are now on an offensive to Marinka-Krasnohorivka, we fight for Pisky-Avdiivka-Ocheretyne, and we are on the offensive to Mayorsk in the direction to Horlivka. Since yesterday -- I will tell you the good news -- the Luhansk People's Republic is also on the offensive, there is also fighting in two directions. Therefore, Kiev will just not be able to be on the defensive in three directions."
From our newsroom:
Russian Deputy Prime Minister Igor Shuvalov on January 23 warned the West against trying to topple President Vladimir Putin and said that Russians are ready to "eat less" and endure other hardships in support of their leader.
Russia has for the past year been sliding into recession amid falling oil prices and Western sanctions against Moscow's role in the conflict in Ukraine.
Shuvalov, speaking at the World Economic Forum in Davos, acknowledged Russia is "going into a longer crisis" compared with seven years ago, when it was affected for about two years by the global crisis.
But he added, "When a Russian feels any foreign pressure, he will never give up his leader. Never. We will survive any hardship in the country -- eat less food, use less electricity."
Moscow says the sanctions are aimed to push Putin from power, but the West denies that.
The comments by Shuvalov, who is believed to be one of the richest men in the government, triggered sarcastic remarks on Russian social media.
An opposition activist posted photos of Shuvalov's Moscow, London and Austria homes to show where he would experience the hardships he described.
Based on reporting by AP