Energy starved North Korea agreed in February to shutdown and seal its key Yongbyon reactor, which produces the raw material for bomb-making plutonium, in return for 50,000 tons of oil from South Korea.

But the North Korean foreign ministry said the shutdown could now occur "without waiting for the total quantity of heavy oil to reach its port."

"(North Korea) is now earnestly examining even the issue of suspending the operation of its nuclear facilities earlier than expected, that is from the moment the first shipment of heavy oil ... is made," the spokesman said in a statement carried by the North's official KCNA news agency.

South Korea promised to send its first shipment of fuel oil to its impoverished neighbour next Thursday, amid efforts to persuade the communist state quickly to shut down its nuclear weapons programme.

The South's Unification Ministry said yesterday that 6,200 tons of heavy fuel oil would leave southeast Ulsan port for the North's Sonbong port on July 12.

The North's decision to consider speeding up the closure was prompted by "the desire to facilitate the process of the six-party talks," the foreign ministry spokesman said.

Six-nation talks -- which involve the two Koreas, Japan, China, Russia and the United States, began in 2003 in an effort to convince North Korea to give up its nuclear weapons programme.

The North tested its first atomic weapon last October.

A timetable for the next six-nation talks may be announced by host China next week, South Korea's chief nuclear envoy Chun Yung-Woo said Friday.

"There's an expectation that China may know each countries' situation by next week and make a decision on a date," Chun said upon arrival at Seoul's airport after a trip to China.

"We can predict a date depending on the arrival of the oil and what action North Korea will take. It would be good for the six-party talks to restart after North Korea shuts down its Yongbyon facilities," he added.