A top North Korean diplomat says Pyongyang has shut down its main nuclear reactor in Yongbyon and will now focus on declaring its nuclear program and disableing its facilities.

The minister for political affairs at the North's mission to the United Nations, Kim Myong-gil, told Voice of America Sunday that the shutdown of the reactor came immediately after the first shipment of 62-hundred tons of heavy fuel oil arrived from South Korea.

Kim said the next steps for the North now include disabling its nuclear facilities, but that these will need American parallel actions including lifting more economic sanctions against North Korea and removing it from the U.S. list of terrorism-sponsoring countries.

The top U.S. nuclear negotiator Christopher Hill told reporters in Tokyo Friday that Washington hopes Pyongyang will conclude disabling its nuclear facilities by the end of the year.

A group of International Atomic Energy Agency inspectors also arrived in Pyongyang late Saturday, and said it will head straight to Yongbyon to begin monitoring activities.