The United States says if North Korea makes a public pledge not to attack South Korea or undertake further provocations that threaten the South, it would be a significant step to improving the situation.

State Department spokesman Philip Crowley said Monday that such a pledge "would be one among many steps that North Korea could take that would convince South Korea that dialogue would be constructive."

Crowley said that the North is in a “charm stage” following last year’s “provocative stage” that was marked by artillery attacks on the South. He stressed that “the charm stage has to be followed up with a real demonstration that North Korea is prepared for sustained and constructive dialogue.”

Crowley added that North Korea will be a key topic of discussion when President Barack Obama and Chinese President Hu Jintao hold a summit on Wednesday of next week.