Foreign Secretary Boris Johnson has postponed a planned visit to Russia in order to attend a meeting with Nato counterparts, including US Secretary of State Rex Tillerson.
The Brussels gathering was rescheduled to March 31 after Mr Tillerson indicated he could not attend on its original planned date of April 5 to 6 because of a US visit by Chinese President Xi Jinping.
But the new date clashes with Mr Johnson's mooted visit to Moscow at the invitation of foreign minister Sergey Lavrov, which would have been the first by a UK foreign secretary in more than five years.
A Foreign Office spokesman said: "We have unfortunately had to postpone the Foreign Secretary's visit to Russia planned this month due to rescheduling of the Nato foreign ministers meeting," said the spokesman.
"The Foreign Secretary has spoken to Foreign Minister Lavrov and looks forward to reinstating his visit as soon as possible."
At the time the visit was announced, Government sources insisted it did not represent an attempt to reset relations with Moscow and that Mr Johnson would take a "robust" line with his Russian hosts.