Moscow has criticized the ministerial meeting, deeming it destructive.
"I believe that there will be nothing productive achieved from this meeting; as long as nothing counterproductive is achieved, that would be a great result already," said Russian Foreign Minister Sergei Lavrov at his annual press conference on Monday.
Washington suggested that while not invited, Russia and China were generally supportive of the Vancouver meeting, which Lavrov flatly rejected as "an outright lie."
Lavrov also questioned the list of countries attending: When we found out about this meeting, we asked: 'Why do you need all those countries together? Greece, Belgium, Colombia, Luxembourg. What do they have to do with the Korean peninsula today?"
Washington says the aim of the gathering is to increase diplomatic and financial pressure on North Korea to give up its development of nuclear missiles and to ensure the implementation of UN sanctions against the country.
China has also hit out at the meeting, saying it will set back peace efforts.
"It will only create divisions within the international community and harm joint efforts to appropriately resolve the Korean peninsula nuclear issue," the Foreign Ministry's spokesman Lu Kang said last week.
Moscow and Beijing have proposed that Pyongyang could freeze its nuclear weapons program in return for a halt to military drills by the US and its allies, that only spiral tensions.