A team of U.N. nuclear inspectors has left for North Korea to monitor the shutdown of the country's main nuclear reactor.

The inspectors' mission, which begins Sunday, will be the first time in nearly five years that North Korea will work with experts from the International Atomic Energy Agency.

IAEA chief Mohamed ElBaradei says he is optimistic that the process will run smoothly. However, he cautioned that the effort to completely shut down Pyongyang's nuclear program will be a "long process," and will depend on the progress of the six-party talks.

China's Foreign Ministry confirmed Thursday that the six-nation talks on dismantling North Korea's nuclear program will resume on July 18 and 19 in Beijing.

Meanwhile, a South Korean ship has departed for North Korea, delivering fuel aid that will help push forward the closure of the North's main nuclear facility.

Pyongyang says it will begin shutting down its Yongbyon nuclear reactor once the initial shipment of fuel aid arrives

The ship departed from the port of Ulsan carrying 6,200 tons of heavy fuel oil. The oil is the first batch of an initial 50,000 tons that was promised to North Korea during six-nation talks in February.

At that meeting, Pyongyang pledged to shut down its main nuclear reactor and dismantle its nuclear weapons programs in exchange for fuel aid and political incentives.

The negotiations between the two Koreas, China, Japan, the United States and Russia have been going on since 2003.

Some information for this report was provided by AFP, AP and Reuters.