Foreign Minister Ban Ki-moon has vowed to closely cooperate with Seoul's allies to deal with North Korea's public declaration that it possesses nuclear weapons.

Ban arrived in Washington Friday to hold discussions with his U.S. counterpart, Condoleezza Rice. Ban originally was planning on discussing ways to bring the North back to the negotiating table, but he said the discussions will now focus on seeking ways of cooperation to deal with the "new situation", referring to the North's declaration

Ban played down the North's move, pointing to similar negative statements it had issued in the past shortly before major negotiations on its nuclear issue.

Ban stressed that Seoul remains committed to finding a peaceful and diplomatic resolution to North Korea's nuclear standoff based on dialogue.