"If North Korea refuses to come back to the six-party talks, then I fully expect we would consult with our partners in the region about the next steps, and that's certainly one possibility," said White House spokesman Scott McClellan.

The six-nation talks involving the two Koreas, China, Russia, the United States and Japan aimed at ending Pyongyang's nuclear arms ambitions stalled after three inconclusive rounds.

North Korea did not show up for a fourth round set for September 2004, and declared in February that it had nuclear weapons for self-defense.

"North Korea previously made a commitment to come back to the six-party talks," McClellan said as US President George W. Bush traveled here.

"North Korea's failure to follow through on that commitment and its provocative words and actions only further isolate it," the spokesman said.