The White House says a reported move by Russia to ban food imports from the United States will only deepen Russia's isolation from the international community.
White House spokeswoman Laura Lucas Magnuson said on August 6 that retaliation by Moscow against Western companies or countries for sanctions imposed earlier by Washington and the European Union will cause further damage to Russia's economy.
She said the Russian Central Bank has previously said that a ban on food imports would increase inflation in Russia.
Some Russian media reports quote Aleksei Alekseenko, a spokesman for Russia's food standards agency Rosselkhoznadzor, as saying that "all food products" produced in the United States would be banned.
He added that all "fruit and vegetables from the EU" will also be banned.
Another report said dairy products from EU countries would also be subject to the ban.
A complete list of the banned food products is expected to be announced on August 7.
U.S. and EU food imports to Russia are worth many billions of dollars annually.
Dale Moore, director of public policy at the American Farm Bureau Federation, told RFE/RL that the Russian ban is "unfortunate" and the "biggest losers in this are going to be the Russian consumers, who are going to be paying more for their food."
The sanctions were announced in a decree signed by Russian President Vladimir Putin earlier on August 6 banning or limiting imports of food and agricultural products from countries that have imposed sanctions on Russia.
The decree 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 against the EU and the United States do not hurt Russian consumers.
Moscow has already imposed bans on certain agricultural imports from Ukraine, Moldova, and several EU countries, including Poland.
The Russian bans follow the latest round of sanctions imposed by the United States and the EU 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 on August 6 said he would not comment on "rumors" that Russia may close its airspace for European airlines, but said "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.