It was the first direct communications between the leaders of the two countries.

The letter was conveyed to DPRK Foreign Minister Pak Ui-chun Wednesday by chief US nuclear envoy Christopher Hill, who was on a visit to the DPRK from Monday to Wednesday.

The president stressed the need for the DPRK to come forward with a full and complete declaration of their nuclear program as called for in a document of the six-party talks, White House spokesman Gordon Johndroe said.

White House press secretary Dana Perino said the president decided to send the letter "so that we can keep it all on track."

The US nuclear envoy, who flew to Beijing on Wednesday afternoon, said yesterday that President Bush had also sent letters to leaders of the other parties involved in the nuclear talks, including Russia, China, South Korea and Japan, to advance the denuclearization process in the Korean Peninsular.

"I think the decision to send a letter out to all the parties was in connection with the very important moment," Hill said in Beijing.

He told reporters that it was possible to have a good draft of the declaration of nuclear programs from the DPRK in a couple of weeks.

According to a six-party talks joint document released in Beijing on Oct. 3, the DPRK agreed to disable all the existing nuclear facilities and provide a complete and correct declaration of all its nuclear programs by the end of this year.

The document said the disablement of the five-megawatt Experimental Reactor, the Reprocessing Plant (Radiochemical Laboratory) and the Nuclear Fuel Rod Fabrication Facility in Yongbyon would be completed by Dec. 31.