No date is agreed yet, but the documentation is expected within a month, the official said, adding that the United States will be able to verify that the DPRK's documentation is complete.

The State Department announced earlier in the day that US nuclear envoy Christopher Hill will take a trip to China and Russia next week for more consultations over the promotion of a nuclear declaration by Pyongyang.

The scheduled visit by the top US negotiator signals Washington's optimism about a long awaited DPRK nuclear declaration, local media said.

"Things are moving ahead," Hill, who is assistant secretary of state, told reporters Thursday when asked about when Pyongyang is possibly submit its declaration of its nuclear program.

"I think the logic of it is they submit it to the Chinese, the Chinese make sure rest of us get a copy of it and then we all look at it and we don't need any six party meeting (to discuss the declaration)," he said.

The DPRK delivered on May 8 the United States more than 18,000 pages of its sensitive nuclear records, and the six-party talks on the nuclear issues on the Korean Peninsula was reportedly to be resumed before June 15 after an eight-month suspension.

The DPRK, which detonated an atomic device in October 2006, has agreed to abandon all its nuclear programs in exchange for economic and diplomatic incentives.

Under an agreement reached at the six-party talks in Beijing in February 2007, the DPRK agreed to abandon all nuclear weapons and programs and declare all its nuclear programs and facilities by the end of 2007, in exchange for diplomatic and economic incentives.

The six-party talks, involving the DPRK, the United States, China, South Korea, Japan and Russia, have been going off and on since August 2003.