WASHINGTON — The former U.S. ambassador to Russia said Friday that he has been banned from traveling there in a tit-for-tat response to U.S. visa bans for senior Russian officials.

Michael McFaul told The Associated Press that he had applied for a Russian visa in order to travel to Moscow in December for possible work on ensuring a smooth transition to a Hillary Clinton presidency, had she been elected. Clinton lost the race to Donald Trump on Tuesday.

McFaul, who served in Moscow from 2012 to 2014 and now works at Stanford University, said he was “extremely disappointed” by the decision. He added that he has traveled to Russia hundreds of times, has many friends there and has spent most of his career studying Russia. “It’s a jarring, very disappointing thing to confirm,” McFaul said.

The U.S. put a group of senior Russian officials on a sanctions list in response to Russia’s annexation of Crimea in 2014. McFaul said he was told by Russian officials that his entry ban was in response to that decision.

The Russian Foreign Ministry confirmed the ban, Russian news agencies reported, citing unidentified sources.

U.S.-Russia ties have sunk to Cold War-lows due to Russia’s actions in Ukraine and Syria. President-elect Trump, who has spoken favorably of Russian President Vladimir Putin, has vowed to improve the relationship.