A spokeswoman for the International Atomic Energy Agency says the agency hopes North Korea will change its mind and allow IAEA inspectors to return. But he says until then the agency has no way of monitoring North Korea's nuclear activities. The statement follows the departure from North Korea earlier Tuesday of inspectors who had been expelled by the North Korean government.

Officials at the International Atomic Energy Agency say now that the inspectors are gone the agency will have to rely on satellite imagery to provide information on North Korea's nuclear program, including a reactor that is believed to be capable of producing plutonium for nuclear weapons.

Until the inspectors are allowed to return to the reactor at Yongbyon, agency officials say they cannot provide any assurances to the international community that North Korea is not producing a nuclear weapon.

The agency's spokeswoman, Melissa Fleming, said the inspectors had been making daily reports until a few days ago. "As of Saturday, they have not been able to carry out their function," she said, "so they traveled back to Pyongyang, packed up their bags and equipment and took out some sensitive documents."

The IAEA says the Yongbyon reactor needs 8,000 fuel rods before it can become operational, and it says 2,000 rods have already been delivered.

North Korea reportedly began disabling IAEA surveillance equipment and removing seals from nuclear sites at Yongbyon earlier this month in preparation for re-activating its nuclear facilities.

Meanwhile, preparations are going ahead for an emergency meeting on January 6 of the IAEA board of governors to discuss North Korea. The 35 member board includes representatives from Japan, China, Russia and the United States.

If North Korea continues to refuse to cooperate with the IAEA, the U.N. agency could ask to the Security Council to intervene.