SEOUL: South Korea and the U.S. rejected North Korea's proposal to start peace talks to formally end the Korean War, with Seoul saying Tuesday that can happen only after the North rejoins disarmament talks and reports progress in denuclearization.

The North, however, said Monday that its return to those negotiations hinges on building better relations with the United States, including signing a peace treaty. The North also called for the lifting of international sanctions against it.

On Tuesday, South Korea's defense chief repeated his country's suspicion of such calls from the North, which regularly pushes for a treaty. Kim Tae-young told reporters he will continue to try to find what the North's true intention is behind the proposal.

Kim added his military is ready to deter any possible North Korean aggression, saying the North "many times in the past offered peace gestures with one hand while on the other committed provocations."

He also repeated a demand from Washington and his own government that any discussion of a peace treaty can only take place after Pyongyang returns to the six-nation nuclear negotiations that it abandoned last year. The allies insist that the North take steps toward disarmament before any concessions on sanctions or a treaty will be made.

"I think it's an issue that we can probably move forward with after the six-party talks are reopened and there is progress in North Korea's denuclearization process," Kim Tae-young said.

Seoul's Foreign Ministry also weighed in, saying it would press ahead with diplomacy to achieve a swift resumption of the disarmament negotiations.

"We urge North Korea to quickly return to the six-way talks and take irreversible steps toward denuclearization," ministry spokesman Kim Young-sun said in a statement.

In Beijing, Foreign Ministry spokeswoman Jiang Yu said China was "waiting to join hands with other parties to promote an early resumption" of those talks.

Earlier, U.S. State Department spokesman P.J. Crowley brushed off the North's call. Speaking Monday in Washington, he urged North Korea to return to the talks "and then we can begin to march down the list of issues that we have."

Washington and Pyongyang have never had diplomatic relations because the 1950-53 Korean War ended in a truce, not a peace treaty, leaving the peninsula technically at war. North Korea, the U.S.-led United Nations Command and China signed a cease-fire, but South Korea never did.

Despite the rejection, the North's top diplomat in Beijing on Tuesday repeated his country's position that it will only resume the nuclear talks after international sanctions on it are lifted.

"If sanctions are lifted, the six-party talks can be held at once," North Korean Ambassador to China Choe Jin Su said in a group interview in Beijing, according to Japan's Kyodo News agency.

He also said the conclusion of a peace treaty will help promote denuclearization "at a rapid tempo," Kyodo reported.

North Korea, which claims it was forced to develop atomic bombs to cope with U.S. threats, called for a peace treaty to be concluded this year, which it emphasized marks the 60th anniversary since the outbreak of the Korean War.

The signing of a peace treaty has been discussed at the six-nation disarmament talks before but has always been based on the assumption that there would be progress in North Korea's denuclearization.

Analysts, including Yang Moo-jin of Seoul's University of North Korean Studies, say the North this time is trying to bring the issue of a peace treaty to the forefront to dilute the issue of nuclear disarmament.

The North quit disarmament talks — which include the two Koreas, China, Japan, Russia and the U.S. — last year in anger over international condemnation of a long-range rocket launch. The country later conducted its second nuclear test, test-launched a series of ballistic missiles and restarted its plutonium-producing facility, inviting widespread condemnation and tighter U.N. sanctions.