US Ambassador Nikki Haley told a Security Council meeting that the United States has evidence of "consistent and wide-ranging Russian violations" of the UN sanctions imposed on North Korea.

"Step by step, sanction by sanction, and time and time again, Russia is working across the board to undermine the sanctions regime," Haley said.

Led by the United States, the council last year adopted three sets of wide-ranging sanctions aimed at cutting off revenue to North Korea's ballistic missile and nuclear programs.

Haley said Russia had been "cheating" despite supporting UN sanctions resolutions.

Russia wants to develop railway links to North Korea to export coal from its Far East region and ultimately reach South Korea to access a global port, Haley said.

"The problem is, it isn't time yet to relieve pressure on North Korea no matter how lucrative it is for Russia," she said.

The United States maintains that UN sanctions which have dealt a blow to North Korea's economy must remain in place until Pyongyang has completely scrapped its nuclear weapons and military programs.

Russia also blocked a US move to blacklist Russian ships allegedly involved in illegal ship-to-ship transfers of refined oil to North Korea.

Haley charged that Moscow was refusing to expel a North Korean operative who is allegedly raising money for Pyongyang's military program and rejecting calls to block his Moscow bank account.

The council meeting was called by the United States after a report by an independent UN panel of experts was amended under pressure from Russia to remove sections that deal with Russian businesses.

The United States blocked the release of the report on the implementation of sanctions in protest at the changes in the latest version.

China called for UN sanctions to be enforced but recalled that resolutions allow for a lifting of the punitive measures if there is progress toward denuclearization.

Chinese Ambassador Mao Zhaoxu said "confrontation is a dead-end" and diplomacy must be "actively" promoted to bring an end to the standoff on the Korean peninsula.

China and Russia have argued that North Korea should be rewarded with the prospect of eased sanctions for opening up dialogue with the United States and halting missile tests.