The State Department says there has been intensified diplomacy but no agreement yet in a U.S.-led effort to salvage the six-party accord under which North Korea committed last year to scrap its nuclear program for aid and diplomatic benefits.
The process has bogged down in a dispute about how to verify the North Korean declaration.
Pyongyang has resisted U.S. verification terms, and also says it should have been taken off the U.S. list of state sponsors of terrorism when it made the disclosure. The Bush administration says de-listing was dependent on an agreed verification plan.
The chief U.S. delegate to the six-party talks Christopher Hill went to North Korea at Pyongyang's invitation last week to discuss the issue and the State Department called the contacts helpful.
There have been news reports of an emerging deal under which Pyongyang would be provisionally removed from the terrorism blacklist if it accepted a revised verification plan and reversed recent steps to restart its Yongbyon reactor complex.
Briefing reporters Friday, State Department Spokesman Sean McCormack had no agreement to announce but suggested one might be near.
He said Secretary Rice had spoken by telephone to the foreign ministers of China, Japan and South Korea and planned a similar call to Russian Foreign Minister Sergei Lavrov to discuss the state of negotiations:
"This has been about getting the details right on a verification regime that we hope will move this process forward so that we can get to the ultimate goal of a de-nuclearized Korean peninsula. That's what these past days and past weeks have been about. So you've had a lot of consultation not only within the U.S. government, putting our best minds to work on this issue -- there's also been a lot of consultation with out partners in the six-party process," she said.
U.S.officials have not discussed the terms of any new verification plan, though Japanese press reports have said it might be limited at first to a focus on plutonium production at Yongbyon.
Some arms control experts have said verification demands on the secretive communist government are too severe, though the Bush administration says they are not unlike terms Libya accepted when it gave up weapons of mass destruction five years ago.
Conservative critics of diplomacy with North Korea have served notice they would oppose any new verification program seen as a retreat from original U.S. terms.
Former Bush administration U.N. ambassador John Bolton says limiting the effort to Yongbyon would be "pathetic," since the facility has been under international scrutiny for some time.
North Korea this week said it was barring International Atomic Energy Agency inspectors from the Yongbyon complex though they remain at housing near the site.
Spokesman McCormack said U.S. observers also remain there but said he did not know if they, too, have been prevented from doing their work.