According to a statement given by the chief of the U.S. nuclear envoy on Thursday, U.S. technicians are likely to begin dismantling by the end of this week North Korea's nuclear complex, which makes weapons-grade plutonium.

The team of U.S. experts arrived in Pyongyang on Thursday to oversee disabling the secretive state's Soviet-era nuclear reactor, a plant that makes nuclear fuel and another that turns spent fuel into plutonium.

Christopher Hill, the top U.S. envoy to six-way talks to end Pyongyang's nuclear arms program, said the U.S. team had "a specific list of measures" and would arrive at the nuclear complex to begin the dismantling process on Friday or Saturday.

The moves follow a breakthrough February deal under which North Korea, which tested a nuclear device last year in defiance of international warnings, is to shut down its Yongbyon nuclear plant and admit U.N. nuclear monitors.

Hill met his North Korean counterpart, Kim Kye-gwan, on Wednesday to discuss steps to disable Yongbyon.

Following lengthy six-party talks in Beijing involving North and South Korea, the United States, Japan, Russia and China, Pyongyang agreed that by the end of 2007 it would have disabled its main nuclear facilities.

This will put it out of the plutonium-production business for about a year, proliferation experts said. But the steps are short of outright destruction.