U.S. special representative for North Korea policy, Stephen Bosworth, has flatly rejected North Korea’s request for the lifting of sanctions as a precondition for a return to the six-way nuclear talks.

In a speech delivered at the Korea Economic Institute in Washington on Thursday, Bosworth said that when Pyongyang comes back to six-party talks and resumes making progress for the goal of denuclearization, the U.N. Security Council will examine the appropriateness of revising a resolution sanctioning the North.

Bosworth urged the North to return to the six-way nuclear talks as he expressed hope that related countries will convene soon to discuss the North’s nuclear issue.

He stressed that even if the nuclear talks do get back on track, a new resolution and political determination on behalf of related parties, including the North, are necessary to reap progress.

Bosworth, who visited Pyongyang in early December, also said that he has no plans for an additional visit to the North.