The U.N. nuclear watchdog and North Korea have reached an agreement on how the agency will monitor and verify shutdown of the country's main nuclear reactor, a top official said Friday.

A team from the International Atomic Energy Agency returned Friday to the North Korean capital from a two-day trip to the Yongbyon nuclear complex, broadcaster APTN reported.

It was the first IAEA visit to the facility since U.N. monitors were expelled from the country in 2002.

"We have concluded this understanding, what our monitoring and verification activities are in principle," IAEA Deputy Director Olli Heinonen said in footage shot by APTN. He did not provide specifics of the agreement.

Heinonen said his team was preparing to report to the IAEA board of governors within one week, but said the timing of the shutdown was up to the six countries involved in North Korea nuclear talks.

"This is for the six parties to decide. You have to ask them the time scale. When they do (decide), we will be ready," he told APTN.

The IAEA team had been invited by North Korea to discuss details of shutting down the reactor, as it pledged under an international accord in February. It was the first IAEA trip to the facility since its monitors were expelled from the country in late 2002.

Secretary of State Condoleezza Rice said in Washington Thursday that she hoped for a swift shutdown of the country's nuclear weapons programs.

"We hope for now rapid progress given the beginning, we believe, of the North Korean efforts to meet their initial action obligations," Rice said before meeting South Korean Foreign Minister Song Min-Soon at the State Department.

North Korea agreed in February to close the reactor in exchange for economic aid and political concessions, under an accord reached in six-party talks also including the U.S., China, Japan, Russia and South Korea.

But the communist nation ignored an April deadline to do so because of a banking dispute with the United States.

That dispute was settled this week after months of delay and North Korea announced Monday that it would move forward with the disarmament deal. That followed a surprise visit last week to North Korea by Christopher Hill, the top U.S. negotiator in the six-party talks.

The accord's initial phase calls for North Korea to shut the Yongbyon reactor and receive 50,000 tons of heavy fuel oil.

South Korea's Unification Ministry said Thursday it had agreed with North Korea to discuss details of the oil aid — such as how much should be shipped to which ports — in talks on Friday and Saturday at the North Korean border city of Kaesong.

Meanwhile, North Korea test-fired three surface-to-surface missiles that landed in the North's territorial waters, according to South Korea's Yonhap news agency and U.S. Defense Department officials.

Yonhap said the tests came on Wednesday, but U.S. officials said it was Tuesday. The discrepancy could not immediately be reconciled.

It was the third time in a month that North Korea test-fired a short-range missile, following launches May 25 and June 7.

The tests could increase tensions over North Korea's nuclear program, although the country is not believed capable of mounting a nuclear weapon on a missile.

Japanese Prime Minister Shinzo Abe slammed the tests, calling them a provocation that defied the United Nations and could destabilize the region.

U.S. officials in Washington also criticized the launches.