"Undoubtedly, a number of countries interested in continuing the conflict will make titanic efforts to disrupt the planned meeting between President Putin and President Trump," he said in a post in his Telegram account, specifying that by efforts he meant "provocations and disinformation".

The Russian president and Trump emissary held talks in Moscow days before the White House deadline for Russia to reach a peace deal with Ukraine.

To allow his visit to happen, the US Treasury Department will presumably have to lift sanctions on Vladimir Putin, as it did when his investment envoy Kirill Dmitriev flew to Washington in April.