A US official charged with enforcing UN sanctions on North Korea sought South Korea's continued support during talks even as Pyongyang makes conciliatory moves after months of military grandstanding.

A high-ranking North Korean delegation led by close aides of leader Kim Jong-il sent to mourn a former South Korean leader met President Lee Myung-bak on Sunday and delivered a message from the North's leader in their first formal communication since Lee took office about 18 months ago.

South Korea's presidential Blue House denied reports in several South Korean newspapers the envoys conveyed a request by Kim for a summit with Lee, who ended years of unconditional aid when he took office and has been roundly vilified by the North.

Analysts said the rare conciliatory gestures from North Korea may indicate that sanctions contained in UN resolutions put in place following the North's long-range rocket launch in April and nuclear test in May could be squeezing the state and forcing it to seek funds for its depleted coffers.

Philip Goldberg, the US coordinator for the UN sanctions on North Korea, met South Korean officials for talks on enforcing the punishments aimed at stamping out the North's arms trade, which estimates say provide it with at least hundreds of millions of dollars a year.

"Our goal is to return to the process of denuclearization," Goldberg told reporters after talks in Seoul.

North Korea has said it considers as dead often-stalled disarmament-for-aid talks among the two Koreas, China, Japan, Russia and the United States. It has signaled that it instead wants only direct dealings with the United States, something Washington said it would not do.

The UN sanctions are designed to ban business with North Koreans suspected of being in the illegal arms trade and with firms trading arms or other illicit materials.

Analysts said enforcing UN resolutions aimed at Pyongyang hinged on neighbor China, the North's biggest benefactor and the closest thing it can claim as a major ally.

But Beijing, which has called on Pyongyang and Washington to talk, has been reluctant to push any punishment that could destabilize the North's leaders and bring chaos to its border.

The North may be swayed into resuming the talks to please China, the host of the discussions, but few analysts expect that it will ever give up its nuclear weapons.

The North may be looking for renewed help from the South, which once supplied aid equal to about 5 percent of its estimated US$17 billion a year GDP.

Despite the North's conciliatory gestures, it maintained a strident tone over a joint US-South Korean military drill that started last week calling it a prelude to nuclear war that could prompt Pyongyang into making a retaliatory strike.

"It is the toughest mode of counteraction of the DPRK (North Korea) to react to the enemy's stick with a sword and its artillery piece with a missile," the North's main newspaper said.