US Secretary of State Condoleezza Rice called North Korea "a completely irresponsible state and dangerous" for its July 5 missile tests.
"When you look at them testing missiles, not telling anybody they're firing them in all different directions, and they're saying that they have a nuclear weapons capability ... That they could make those together is very dangerous," Rice told a group of Asian journalists on Friday.
Rice stressed that last week's UN Security Council resolution criticising Pyongyang's test launches shows "that this is a problem that North Korea has with the entire international community."
She added that she would be happy to attend a meeting of the six parties trying to resolve the North Korean nuclear problem if it is organised during the Association of South East Asia Nations Regional Forum next week in Kuala Lumpur.
Rice confirmed she would attend the meeting following her trip to the Middle East to try to help find a framework for peace in the embattled region.
Host Malaysia had earlier warned that Rice, who skipped the meeting last year, would send a negative message with another no-show.
She told the Asian reporters the US had three aims for the ASEAN meeting: to deepen relations between the US and the 10-member group; to talk about cooperation on terrorism and weapons proliferation, and especially North Korea; and to discuss the Middle East conflict, particularly with countries that are taking a strong interest in it like Malaysia and Indonesia.