The Republic of Korea's (ROK) officials will make a rare visit to the Democratic People's Republic of Korea (DPRK) tomorrow to check Pyongyang's progress in sticking to an international nuclear disarmament deal, officials in Seoul said.

The trip will be the first high-level ROK government delegation to visit Pyongyang since President Lee Myung-bak took office in February 2008 and is one of a handful of nuclear teams from the ROK ever to visit the DPRK.

Pyongyang threatened to reject all attempts to inspect the core of its nuclear arms program, with the foreign ministry saying in a statement yesterday that the US must first end its "hostile policy" toward Pyongyang.