South Korea's pointman on Pyongyang left for China on Monday for talks that will focus on North Korea, amid diplomatic efforts to revive stalled multinational disarmament negotiations.
Unification Minister Yu Woo-Ik will meet Vice Foreign Minister Zhang Zhijun, Foreign Minister Yang Jiechi, State Councillor Dai Bingguo during his three-day trip, his ministry said.
China hosts six-party talks on the North's nuclear programmes which began in 2003 and also include the two Koreas, the United States, Japan and Russia.
The nuclear-armed North quit the forum in April 2009, a month before its second atomic weapons test.
Pyongyang now says it wants to come back without preconditions, but the US and its allies say it should first take action to show it is serious about the process.
In particular, they want the North to shut down a uranium enrichment plant which could be reconfigured to produce bomb-making material.
Yu visited the United States earlier this month for consultations, and a senior US State Department official was due to arrive in South Korea late Monday.
Under Secretary of State for Political Affairs Wendy Sherman will meet senior Seoul officials Tuesday "to explore how to expand the depth and breadth" of the US-South Korean alliance, the State Department said.
The two sides pledged to strengthen their military alliance after two deadly border incidents last year.
The South accused the North of torpedoing a warship which sank near the disputed maritime border with the loss of 46 sailors in March 2010.
The North denied responsibility but shelled a South Korean border island last November 23, killing four people including civilians.
In recent months there have been signs of a slight thaw in cross-border relations, but the South has threatened to hit back hard for any fresh attack.
"We need thorough punishment against provocations by the enemy," Defence Minister Kim Kwan-Jin said Friday in an order marking the first anniversary this Wednesday of the island attack.
