The White House said on Thursday that the two sides had held their first face-to-face meeting in five months on 12 May amid increasing signs Pyongyang is taking steps to advance its nuclear weapons plans and indications of a key shift in US policy.
"This channel was used to reiterate the message directly that the North Koreans need to return to the six-party talks without conditions," White House spokesman Trent Duffy told reporters.
South Korean aid
Ending four days of separate bilateral talks, South Korea agreed on Thursday to ship 200,000 tonnes of fertiliser to the North after requests from its impoverished neighbour to ease food shortages that aid officials say could worsen.
The South's attempt to have the North recognise the seriousness of the crisis over its declared nuclear arsenal had extended the talks beyond Tuesday.
S Korea will send 200,000 tonnes
of fertiliser to N Korea
But there was no direct mention of the crisis in the joint statement issued in the North Korean city of Kaesong.
South Korean media seized on this to criticise the government, although analysts said Seoul did the best that could have been expected by securing renewed ministerial talks.
Aid not mentioned
The North's official KCNA news agency report on the talks did not mention the fertiliser aid.
"Despite the Roh Moo-hyun government's pledge that the South will play a leading role in resolving the nuclear crisis, Seoul proved powerless to deal with it," said the newspaper Dong-a Ilbo in an editorial, referring to the South Korean president.
Another newspaper, JoongAng Ilbo, took a similar line, saying it would be interesting to see how Washington reacted to the meeting, which it described as trading a huge amount of fertiliser for only a promise of more meetings.
The two sides agreed to hold ministerial talks in Seoul from 21 June to 24 June and for Unification Minister Chung Dong-young to visit Pyongyang for events to mark the fifth anniversary of the 15 June, 2000, summit between the leaders of the two Koreas.
Some media said Chung would be hoping to meet North Korean leader Kim Jong-il but Dong-a Ilbo said it expected little from that trip because the North's main focus was the United States.
"At the ministerial-level talks, the South will be able to do more to put the nuclear issue on the table"
Korea Institute for National Unification
But some analysts said restoring dialogue was an achievement given the time it takes to build any relationship with the North.
"At the ministerial-level talks, the South will be able to do more to put the nuclear issue on the table," said Jeung Young-tae, a North Korea expert at the Korea Institute for National Unification.
Another expert said it was unrealistic to have expected a North Korean commitment on the nuclear crisis.
"The South did enough by trying to link bilateral issues with the nuclear problem," said Paik Hak-soon of the Sejong Institute.
With concern Pyongyang may conduct an underground test of a nuclear device, and with the six-party talks looking increasingly fragile, Washington was under pressure from its own partners to open some form of dialogue.
Negotiations involving North and South Korea, China, Japan, Russia and the United States and aimed at dismantling the North's nuclear capabilities have not been held since June 2004 because Pyongyang refused to set a date.
The United States on Wednesday promised expanded bilateral engagement with North Korea if it returns to the talks.
"We are willing to return to the six-party talks," the top North Korean delegate to the bilateral talks, Kim Man-gil, told South Korean pool reporters. But he repeated Pyongyang's position that Washington must first provide the right conditions.
Arms experts say the impoverished North's nuclear programme has diverted funds from the rest of the economy for decades. A lack of fertiliser and farm machinery has contributed to the North's food shortages.
Experts say N Korea's nuclear
programme has diverted funds
"These factors combined to make it impossible for the country to feed itself and therefore heavily dependent on outside assistance, which is now dwindling quite dramatically," Gerald Bourke of the World Food Programme told Radio Free Asia.
The Asian Wall Street Journal reported the United States had cut off all its food-aid shipments to the North so far this year.