The assessments of U.S. and British spies on Ukraine cannot be trusted, given the number of grave mistakes that were made in the run up to the U.S.-led invasion of Iraq, Russia's first deputy permanent representative to the United Nations said on Sunday.

"We don't trust U.S. or British intelligence. They let us down, the whole world, on many occasions. It's enough just to remember the 'weapons of mass destruction' in Iraq," Dmitry Polyanskiy said to Sky News.