MOSCOW — Russian health regulators announced formidable new barriers to the import of meat from the United States late on Friday, in a move some analysts saw as retaliation for American legislation punishing Russian officials linked to human rights violations.

The new Russian regulation requires imported meat to undergo testing for and be certified free of ractopamine, which is added to animal feed in the United States to make meat more lean.

The United States Department of Agriculture considers ractopamine safe and does not test for it. The United States exports about $500 million worth of beef and pork to Russia.

A notice published on the regulator’s Web site on Friday said the regulation would go into force immediately, and that during an unspecified “transition period” Russia will conduct its own testing. After the transition period ends, foreign countries will be required to certify their meat exports as ractopamine-free.