North Korea says banning nuclear weapons from the Korean peninsula should be the main goal of the six-party talks that resumed Tuesday in Beijing.

But during the opening session Japan's chief negotiator, Kenichiro Sasae, raised the issue of North Korea's abduction of Japanese citizens during the 1970s and 80s, despite objections from South Korea.

Chief U.S. negotiator Christopher Hill said in his opening statement that the United States views North Korea as a sovereign nation and that Washington has "absolutely no intention" of attacking the Stalinist state.

This fourth round of talks involving the two Koreas, the United States, China, Japan and Russia is aimed at convincing Pyongyang to abandon its nuclear ambitions. North Korea had boycotted the negotiations for more than a year, citing a hostile U.S. policy.