The United States on Tuesday dismissed a proposal by the Democratic People's Republic of Korea (DPRK) on negotiating a peace treaty, saying the first and foremost thing for Pyongyang is to return to the six-party talks.

"The appropriate next step is for North Korea to return to the six-party talks and to resume deliberations in this context. And within that context, it's possible to have bilateral interactions and other discussions, not just with the United States but with other countries," said Kurt Campbell, Assistant Secretary of State for East Asian and Pacific Affairs.

Pyongyang on Monday renewed its demands of negotiating a peace treaty and lifting sanctions before it would return to the six- party talks, saying failure for the discussion on concluding a peace treaty to start would consequently "push back the process of denuclearization."

"The U.S. position, which is very firm and in close coordination with our allies and friends in the six-party talks, is that it would be inappropriate at this juncture to lift sanctions or to revisit aspects of UN Security Council Resolution 1874, given the current circumstances," said Campbell.

"It's important that North Korea make clear that they are prepared to abide by previous agreements in 2005 and 2007," he added.

The DPRK shut down the Yongbyon nuclear facilities in 2007 under a six-nation nuclear disarmament deal. However, Pyongyang quit the multilateral talks in April 2009 in anger over international criticism of its long-range rocket test.

It conducted an underground nuclear test in May and declared it was in the final phase of an experimental, highly enriched uranium program -- another way to make an atomic bomb.

However, tensions began to ease recently, and the DPRK has expressed willingness to return to the six-party talks involving itself, the United States, China, the Republic of Korea, Japan and Russia, if it had satisfactory talks with Washington.

In early December, the two countries agreed on the need to resume the negotiations during a trip by President Barack Obama's envoy to Pyongyang. Washington has been trying to persuade Pyongyang to return to the stalled six-party talks, while Pyongyang wants permanent peace and normalization of relations with the United States before its denuclearization.