"When we understood that sanctions are not only not frozen or lifted, but are also expanding and deepening, we also responded and insisted that the number of American diplomats in Russia and Russian diplomats in the U.S. be equal," Lavrov said in an interview with Rossiya-1 TV channel, according to the transcript of the interview published by the Russian Foreign Ministry.

In March 2018, Russia announced the decision to expel 60 U.S. diplomats and close the U.S. consulate general in St. Petersburg, in retaliation to Washington's move to expel 60 Russian diplomats and intelligence officials in the United States.

Lavrov expressed regrets the U.S. Congress stood in the way of U.S President Donald Trump's efforts to bring relations with Russia back on track.

"I repeat, we are ready at any time to resolve these issues on the basis of the 'zero option' and return to the normal functioning of our diplomatic institutions," Lavrov said.

He said that he had already discussed the issue with U.S. Secretary of State Mike Pompeo and U.S. Ambassador to Russia Jon Huntsman, who understands that "sometime we must return to this. The sooner, the better."

The "zero option" refers to an American proposal for the withdrawal of all Soviet and United States intermediate-range nuclear missiles from Europe.

On August 2, Russia and the United States formally withdrew from the Intermediate-Range Nuclear Forces (INF) Treaty after accusing each other of violating the landmark arms control deal.