Russian President Vladimir Putin has signed a decree banning or limiting imports of food and agricultural products from countries that have imposed sanctions on Russia.
The decree, whose text was released on August 6, says such imports will be "banned or restricted" for one year.
Putin also ordered his government to come up with a list of goods whose imports are to be banned or restricted.
On August 5, Putin said the government should make sure any retaliatory measures do not hurt Russian consumers.
Moscow has already imposed bans on certain agricultural imports from Ukraine, Moldova, and several EU countries.
The Russian bans follow the latest round of sanctions imposed by the United States and the European Union last month, which for the first time targeted entire sectors of the Russian economy.
The sanctions target Russia's oil and defense industries, and limit the access of state-owned Russian banks to Western financial markets.
Putin's decree says the restrictions are being imposed "with the goal of guaranteeing the security of the Russian Federation."
State statistics show Russia imported about one-third of its food from abroad in the past decade.
Russia buys fruit and vegetables from the EU worth an annual 2 billion euros ($2.8 billion), and food and agricultural products from the United States worth about $1.4 billion.
Meanwhile, Russian Foreign Minister Sergei Lavrov said on August 6 he would not comment on "rumors" that Russia may close its airspace for European airlines, but said that "our Western partners should think about companies and their citizens."
Earlier this week, the Russian business daily "Vedomosti" reported that Russia was considering "restrictions or even a ban on transit flights by European airlines to Asia over Russian territory" in retaliation for EU sanctions that have targeted Russia's low-cost airline Dobrolyot.
Such a move would significantly increase the cost of flights from Europe to Asia as they would be forced to take longer routes avoiding Russian airspace.