SEOUL, Oct. 2 (Yonhap) -- The United States and North Korea are likely to hold their second round of nuclear disarmament talks later this month, after a summit meeting between the South Korean and U.S. presidents, a senior government official in Seoul said, stressing the allies' close cooperation on the issue.

Media speculation has been rife over the timing of the next meeting between Washington and Pyongyang, as multilateral efforts are underway to revive the long-stalled six-party talks on ending the North's nuclear weapons programs. Since July, South Korea and the U.S. have engaged in a series of bilateral talks with the North to discuss preconditions for the resumption of the six-way forum.

South Korea and the U.S. demand a halt to all nuclear weapons activities, including the North's recently revealed uranium enrichment program (UEP); a moratorium on nuclear and missile testing; and the return of U.N. inspectors to North Korea's nuclear sites. North Korea, meanwhile, is pushing for the unconditional resumption of the talks, which offer economic and political aid to the North in exchange for its nuclear disarmament.

The six-party negotiations, also involving China, Japan, and Russia, have been dormant since Pyongyang quit in April 2009 and conducted its second nuclear test a month later.

"I expect the U.S. and North Korea to hold their second round of talks (in October), but I don't think the date has been fixed yet," the South Korean official said Friday, speaking on condition of anonymity.

"I think they'll decide on the date after summit talks are over between President Lee and President Obama, and after the two nations coordinate their position," the official said during a workshop with reporters in Hwaseong, some 45 kilometers southwest of Seoul.

President Lee Myung-bak is scheduled for summit talks with his U.S. counterpart in Washington on Oct. 13. The two sides are expected to discuss their countries' alliance, economic cooperation and North Korea, according to the South Korean presidential office.

The official noted that if the six-party talks reopen, North Korea's UEP will be at the top of the agenda. Many fear that the facility gives North Korea a second way to build atomic bombs, in addition to its known plutonium-based program.

"North Korea argues it is part of its peaceful use of nuclear energy, but in fact the program allows them to (develop nuclear weapons) far more secretly than the plutonium-based program, so it is an important issue that needs to be resolved," the official said.

He also said the North's nuclear weapons drive affects the Koreas' reunification in the long run.

"Our country's economy ranks among the world's top 20 and the two Koreas' combined population is around 70-80 million. If (such a nation) possesses nuclear weapons, I don't think our neighbors will accept reunification," he said.