US President George W. Bush has written letters to Kim Jong-Il, leader of the Democratic People's Republic of Korea (DPRK), and the four other parties in nuclear talks, urging Pyongyang to fully disclose its atomic activities, the White House said yesterday.

"President Bush wrote letters to all the leaders involved in the six-party talks last Saturday, December 1," US National Security Council spokesman Gordon Johndroe told reporters.

"In these letters, the president reiterated our commitment to the six-party talks and stressed the need for North Korea (DPRK) to come forward with a full and complete declaration of their nuclear programs, as called for in the September 2005 six-party agreement," Johndroe said.