US Assistant Secretary of State Christopher Hill ruled out a military response by Washington over Pyongyang's continued refusal to freeze its nuclear weapons program and its snubbing of multilateral talks to end the crisis.

But among other measures, Washington will see to it that North Korea would not be able to counterfeit American currency and get its hands on new missile technology, he said.

"We're going to do everything we can do to make it difficult for the North Koreans to do that," Hill said during a university forum in Manila.

"We are also going to do everything we can do to make it difficult for them to produce these weapons," he said.

Hill said Washington was prepared to work closely with China in trying to woo the Stalinist North back to the negotiating table.

"We don't want to consider this as a bilateral issue. We are going to do this multilaterally," Hill stressed.

"We want to solve this through diplomatic means," he said.

"As we go forward from here, we can work closely with the Chinese government to bring the North Koreans" back to the negotiating table, Hill said.

In regional security talks in Kuala Lumpur on Friday, US Secretary of State Condoleezza Rice urged North Korea to rejoin six-nation negotiations on its nuclear programme. She said the United States was ready "at any time, at any place and without any conditions" to meet it under the six-nation talks framework that began three years ago.

But the North, which left the talks in November and caused outrage earlier this month when it test-fired seven missiles, said it would not return until US financial sanctions against it were dropped.

It said it was also considering withdrawing from the Association of Southeast Asian Nations Regional Forum, one of the few diplomatic gatherings it attends.