North Korea's nuclear programs were on the agenda Monday for a summit between the Chinese and South Korean presidents amid recent angry rhetoric from Pyongyang.

Chinese President Hu Jintao was due to arrive for a two-day state visit to South Korea, flush with his country's success in hosting its first Olympic Games, which concluded Sunday.

The two leaders will hold in-depth consultations on "advancing the six-nation talks" aimed at ending North Korea's nuclear programs, according to comments posted on South Korea's presidential Web site.

China, North Korea's key ally and main aid donor, has chaired numerous rounds of disarmament talks since 2003 on the North's weapons programs. The talks — which also involve the U.S. the two Koreas, Russia and Japan — have produced a landmark aid-for-disaramament deal.

In June, North Korea demolished its nuclear reactor's cooling tower and submitted its long-delayed nuclear declaration. The North, however, remains at odds with the U.S. over how to verify the declared nuclear programs.

North Korea has accused Washington of delaying its removal from a U.S. terrorism blacklist. Washington has said it will drop North Korea from the list only after it agrees to a full nuclear verification plan.

North Korean state media carried a series of dispatches criticizing the U.S. last week and blasting U.S.-South Korean computer-simulated war games. The North's Foreign Ministry said Pyongyang would bolster its "war deterrent" — a euphemism for its nuclear programs — amid "military threats" posed by the U.S.

At the summit in Seoul, Hu and Lee were also expected to discuss action plans for the "strategic cooperative partnership" pledged at their first summit in Beijing in May.

The new partnership includes dialogue between their foreign ministries and cooperation in areas such as trade, environmental protection and nuclear energy.

The two leaders are scheduled to sign several memorandums of understanding on such issues as cooperation in energy and high-tech fields, according to Lee's office.

China is South Korea's largest trading partner, with two-way trade volume reaching $145 billion last year.