Reuters wrote that the CIA, the U.S. Central Intelligence Agency, declined to comment on the trip by John Ratcliffe, the head of the agency, to Moscow to meet with Russian officials.

Dmitry Peskov, the Kremlin spokesman, also said that Vladimir Putin, the Russian president, has no plans to meet with Ratcliffe.

A person familiar with the matter told Reuters that the United States had asked Ukraine not to carry out air attacks around Moscow, St. Petersburg, and some northern regions of Russia on Monday, Tuesday, and Wednesday this week, because a plane carrying a senior U.S. official is scheduled to fly to the Russian capital.

The source declined to provide further details.

The Financial Times was the first outlet to report on the U.S. message to Ukraine.