BEIJING - Chinese Foreign Minister Yang Jiechi is to meet North Korean leader Kim Jong-il later on Tuesday, a ministry spokesman said, as uncertainty continued over when Pyongyang may shut its nuclear reactor.

Chinese Foreign Minister Yang Jiechi, left, meets Vice North Korean Foreign Minister Kim Yong Il in Pyongyang, Tuesday, July 3, 2007, in this image made from TV. [AP]

Yang, who arrived in Pyongyang on Monday, earlier met the North Korean foreign minister and other officials to discuss expanding cooperation, in particular trade ties, Foreign Ministry spokesman Qin Gang told a regular news conference in Beijing.

He gave no details of Yang's scheduled meeting with Kim.

Qin said the officials had agreed to work towards implementing a February agreement aimed at scrapping Pyongyang's nuclear programme in exchange for energy assistance and security guarantees.

"Both sides positively evaluated bilateral relations and reached agreement on strengthening cooperation," Qin said.

He said Yang would "express China's consistent stance on using peaceful means and consultation and dialogue to resolve the Korean peninsula nuclear issue".

Yang, making his first visit as foreign minister to North Korea, is expected to leave on Wednesday.

His trip follows a visit by officials from the U.N.'s nuclear watchdog last week after North Korea agreed to move ahead on a disarmament-for-aid deal reached at six-party talks in February.

China hosts the disarmament talks that also include South Korea, the United States, Japan and Russia.

The six reached a deal on February 13 under which North Korea would receive energy aid, security guarantees and better diplomatic standing in return for ending its nuclear arms programmes, starting by closing its Yongbyon reactor.

The agreement stalled over some $25 million in North Korean funds which a Macau bank had frozen under U.S. pressure. Pyongyang demanded that it receive the money before proceeding, but it took weeks for U.S. officials to work out how to send it.

Now new uncertainty has emerged over when North Korea will shut down Yongbyon, which produces plutonium that can go into nuclear weapons.

North Korea has said it first wants to receive some promised fuel oil shipments, Washington officials have told Reuters.

Chief U.S. negotiator Christopher Hill said last week he wanted Pyongyang to close Yongbyon before holding a new round of six-country talks, possibly next week.

But the Washington officials said Pyongyang had told South Korea, which is providing the oil, and the International Atomic Energy Agency that it wanted at least some of the heavy fuel oil before the reactor closes.