Several current and former U.S. diplomats said they anticipate the post of U.S. ambassador to Russia could be vacant for months or longer.

It is noted that the reason is the existing difficulties in relations between Russia and the United States.

On September 4, John Sullivan completed his work as US Ambassador to Russia and left Moscow.

The State Department said that the US authorities will soon announce the candidacy of a new ambassador to Russia.

According to the newspaper Politico, Sullivan attributed his unexpected completion of work to the illness of his wife, who died on Monday, September 5.