South Korea has agreed to resume high-level talks with North Korea that could restart major aid shipments despite calls for caution over an international deal on the North's nuclear programmes.

Just two days after North Korea agreed to disable nuclear facilities in return for aid and diplomatic concessions, officials from the two Koreas met to set up the bilateral ministerial talks.

Their unification ministers will hold four days of negotiations in Pyongyang from February 27, the first such meeting in seven months.

Seoul officials have said the meeting could pave the way for the resumption of rice and fertiliser aid worth millions of dollars to the impoverished North.

In Washington, US President George W. Bush hit back at critics of the deal but urged the communist North to live up to its commitments.

The ministerial talks were suspended last July after North Korean missile tests sparked international alarm. The North then carried out its first atom bomb test in October.

The regular aid shipments have remained suspended since the missile tests.

Conservative critics of the Seoul government's "sunshine" engagement policy with the North say it is too soon to resume aid.

Under the accord, North Korea will be given 50,000 tonnes of fuel aid for closing its Yongbyon nuclear facility within two months and allowing UN atomic inspectors back in.

It would eventually receive one million tonnes if the accord advances as planned and it permanently disables key facilities.

The United States would begin the process of delisting the North as a sponsor of terrorism and normalising relations.

But there is no agreement yet on getting rid of the North's plutonium stockpile, estimated to be sufficient to make six to eight more bombs.

Bush had called Japanese Prime Minister Shinzo Abe and South Korean President Roh Moo-hyun, and they agreed to work together to ensure North Korea keeps its side of the pact.

At his press conference Wednesday, he defended the deal against critics, including from his key conservative base, who said North Korea is being rewarded for bad behaviour.

Among them was Washington's former envoy to the United Nations, John Bolton, who said the agreement undercut UN sanctions and was "a very bad deal" when Washington is challenging Iran over its nuclear programme.

"I strongly disagree with his assessment," Bush retorted, saying he had "an obligation to try all diplomatic means necessary."

The US leader went on: "Now, those who say the North Koreans have got to prove themselves by actually following through in the deal are right, and I'm one."

Bush promised to step up food aid to the impoverished North if Kim Jong-Il's regime took "verifiable measures" to end its weapons programme.

PHOTO CAPTION

South Korean Unification Minister Lee Jae-Joung (R) talks to reporters after a send-off for the delegation for working-level talks at the government office in Seoul. (AFP)

AFP