SEOUL: South Korea and the United States will not be swayed by North Korea's peace overtures unless it gives up its nuclear weapons, Seoul's foreign ministry said Monday.

Senior visiting North Korean officials met President Lee Myung-Bak Sunday to deliver a verbal message from their leader Kim Jong-Il, the latest in a series of conciliatory gestures by the communist state after months of sabre-rattling.

"Both countries have agreed that the South Korea-US response would remain unchanged unless there is a fundamental change to North Korea's attitude toward denuclearisation," said ministry spokesman Moon Tae-Young.

Seoul officials earlier held talks with the US special envoy on North Korea, Stephen Bosworth, and the US diplomat tasked with enforcing United Nations sanctions, Philip Goldberg.

Moon said Seoul and Washington would "faithfully implement" the sanctions resolution "while leaving the door always open for dialogue and urging North Korea to return to six-party talks."

Kim's message to Lee -- frequently vilified by the North's media as a "traitor" and US sycophant -- was not disclosed.

But both sides in the presidential talks expressed hopes for warmer relations after more than a year of heightened cross-border tensions.

International anxiety has also risen since the North's missile and nuclear tests earlier this year and the subsequent UN sanctions.

Goldberg held talks earlier Monday with South Korean nuclear negotiator Wi Sung-Lac during a regional tour.

"The effort overall is to bring about a return to denuclearisation and an end to those missile programmes that are violations not just of the UN resolution but also a previous commitment made by North Korea with the six-party talks," he told reporters afterwards.

The North walked out of the six-nation nuclear disarmament talks in April and has instead sought direct dialogue with Washington.

Goldberg reiterated that the US would hold bilateral talks only within the six-party framework, which also includes South Korea, China, Japan and Russia.

Inter-Korean relations have been icy since the conservative Lee came to power in February 2008. He scrapped a "sunshine" aid and engagement policy and linked economic assistance to the North's nuclear disarmament.

Critics of the decade-long "sunshine" policy say it failed to halt the North's drive for nuclear weapons, and may even have indirectly funded it.

Lee's office Monday denied newspaper reports that Kim Jong-Il in his message proposed another summit to settle differences.

Kim had sent his delegation to join mourning for former president Kim Dae-Jung, who held the first summit in 2000. A second was held in 2007.

The two sides held only general talks on developing relations "and no issues related to an inter-Korean summit... were discussed," the office said in a statement.

"The government's consistent North Korea policy is that we will help North Korea if the North gives up its nuclear ambitions," chief presidential spokesman Lee Dong-Kwan said.

Some analysts see Pyongyang's softer line this month as an attempt to ease the impact of the sanctions.

Leader Kim pardoned two jailed US journalists after former president Bill Clinton visited Pyongyang.

The North also freed a South Korean detainee and announced willingness to restart lucrative tourist trips and family reunions for South Koreans. It lifted tough restrictions on border crossings.

But the ruling party newspaper Rodong Sinmun again blasted an ongoing US-South Korean military exercise as a rehearsal for a nuclear war against the North.

"The US once again stripped bare its true colours as a nuclear war maniac, the country negating dialogue and disturber of peace," it said.