China called the Vancouver international meeting on North Korea "illegal", as major players like Beijing and Moscow were not present, AFP reported.
The absence of Russia and China from the two days of talks in Vancouver, which began on Monday, shows the holes in Washington's bid to form a unified global front against North Korea's nuclear threat.
"The most important relevant parties of the Korean peninsula issue haven't taken part in the meeting so I don't think the meeting is legal or representative," Chinese foreign ministry spokesman Lu Kang told a regular briefing.
Lu denounced the "Cold War mentality" of "relevant parties" -- without naming nations.
China, which is North Korea's main economic and diplomatic ally, has criticised the Vancouver talks and called for sanctions discussions to remain within the United Nations framework.