The U.S. has urged North Korea to showcase its commitment to denuclearization with concrete actions in order to resume the six-party nuclear talks.

In a daily news briefing, State Department spokesman Philip Crowley said that if North Korea wants to engage seriously in the six-party process, there are very specific actions that Pyongyang has to take first before the U.S. would consider a resumption of the multilateral dialogue.

The statement follows the North's pledge to denuclearize and to seek the signing of a peace agreement through the six-way dialogue.

He said that if the North wants to engage in the six-party process, it must fulfill the commitments specified by the 2005 joint statement. Crowley added, however, that there’s been no indication that the North is prepared to do that.

He said the sinking of South Korea’s “Cheonan” warship was a profound violation of the existing armistice.