Kremlin says Black Sea grain deal can't 'stand on one leg', 'horrible' Ukraine beheading video has to be 'verified'

The Kremlin on Wednesday said the Black Sea grain initiative could not "stand on one leg" and that the outlook for the deal was not great as promises to remove obstacles to Russia's agricultural and fertiliser exports were not being fulfilled.

The Kremlin also said the authenticity of the "horrible" images showing an alleged decapitation of a Ukrainian prisoner of war has to be verified.

"First of all, the authenticity of this horrible footage needs to be verified," Kremlin spokesman Dmitry Peskov told reporters, adding that "we live in a world of fakes."

He added that it was unclear whether leaked U.S. documents saying that U.S. and British special forces were in Ukraine were real, but that it had already known that instructors from NATO countries were taking part in military actions in the country.