Pyongyang agreed in February 2007 to halt its nuclear programs and provide full information by late 2007 in return for economic aid and diplomatic incentives. However, North Korea missed the deadline, causing six-nation talks, involving China, Japan, Russia, the U.S. and the two Koreas, to stall in January.
"North Korea will likely submit the declaration probably at night," South Korea's Yonhap news agency said citing a diplomatic source.
The nuclear declaration, expected to be 40-50 pages, will provide details on the North's nuclear plants and materials including the country's plutonium stock. The North is expected to hand over the document through its embassy in Beijing, which has hosted the six-party talks since August 2003.
Meanwhile, U.S. Assistant Secretary of State Christopher Hill said Pyongyang's nuclear declaration is unlikely to cover the country's atomic weapons, the news agency added.
After the declaration has been submitted, the U.S. plans to start initial steps to strike North Korea off its blacklist of countries sponsoring terrorist groups and organizations, which also includes Cuba, Iran, Sudan and Syria.
Inclusion on the blacklist prevents North Korea from receiving low-interest World Bank loans. It also prevents the country from receiving loans from other international lending agencies.
In late April, Washington released previously classified video and photographic evidence that it said proved North Korea had helped Syria build a nuclear reactor.
The report related to a site destroyed in September last year in an Israeli airstrike, an incident that had until then remained shrouded in secrecy, and came amid mounting pressure on North Korea.
