SEOUL, South Korea (AP) – North Korea has agreed to allow a U.S. delegation to visit its main nuclear complex next week, the first such inspection since the isolated communist country expelled United Nations monitors more than a year ago.

The visit appeared to be an effort by North Korea to prove that it has built a nuclear bomb – or capable of doing so – and strengthen its negotiating position ahead of planned talks with the United States and four other nations on ending the nuclear standoff.

Pyonyang could also be signaling its willingness to allow more extensive inspections in the future – if Washington meets its demands for humanitarian aid and a promise not to attack the North.

USA Today reported Friday that Washington approved the trip to North Korea’s main nuclear facilities at Yongbyon, north of Pyongyang and it was scheduled for Jan. 6-10.

“The report is true,” an official at the South Korean Foreign Ministry told The Associated Press. “The U.S. side has informed us of the trip.”

Jason Rebholz, a spokesman of the U.S. Embassy in Seoul, said he had no information on the trip and could not comment on the news report.

It was unclear how much access to key facilities the North would give to the U.S. experts. U.N. monitors never had full access to the Yongbyon facilities, believed to be the center of the North’s weapons program, before they were thrown out in late 2002.

The North says it has completed reprocessing 8,000 spent nuclear fuel rods at Yongbyon in a process that can yield enough plutonium for half a dozen atomic bombs. North Korea is believed to already have one or two nuclear bombs.

The developments in the North Korea nuclear standoff came after breakthroughs in other nations whose nuclear programs have been a concern to the United States. Libya announced last month that it was renouncing its nuclear efforts and would open up its facilities to the United Nations, while Iran consented to U.N. inspections – though it will continue with a nuclear program it insists is peaceful.

North Korea’s invitation of U.S. experts could mean that the communist regime wants to prove that it is using plutonium to build bombs, and to increase its leverage at upcoming six-nation talks, said Ko Yoo-hwan, a North Korea expert at Seoul’s Dongkuk University.

For weeks, North Korea has said it was boosting its nuclear weapons program and was willing to demonstrate its nuclear capabilities in a “physical” manner. It invited a U.S. congressional delegation led by Curt Weldon, vice chairman of the Armed Services Committee of the U.S. House of Representatives, to visit Yongbyon in October, but the White House blocked the visit.

In its New Year’s Day message, North Korea reconfirmed that it wants to resolve the dispute peacefully, through six-nation talks with the United States, China, Russia, Japan and South Korea.

China has been trying to put together a second round of the six-nation talks for early this year, after an August session ended without agreement or a date for a new meeting. The United States is trying to persuade the North to give up its nuclear program in return for aid and better ties with the outside world – but the sides are divided over exactly what concessions to make and when.

Last month, North Korea said that as a first step toward resolving the nuclear crisis, it would freeze its nuclear weapons program and allow inspections if the United States provides free oil shipments and economic aide and take its name off the State Department’s list of terrorism-sponsoring countries.

The U.S. visit to Yongbyon could be a signal from the North that it is willing to open the site further.

“I don’t think North Korea will let the U.S. delegation conduct a formal inspection or verification of its nuclear program during its visit,” Ko said. “But it does show that it is willing to let outsiders see its facilities and is ready to work out a deal.”

The U.S. government wants North Korea to halt weapons efforts before it makes concessions on aid, the terror list or security guarantees.

The nuclear standoff flared in October 2002 when U.S. officials said Pyongyang admitted having a secret nuclear program in violation of a 1994 pact. It soon after expelled inspectors and, in early 2003, bowed out of the Nuclear Non-Proliferation Treaty.

The American delegation due to visit Yongbyon will include U.S. Senate policy aides, the South Korean official said on condition of anonymity. He refused to reveal further details, saying more details will be announced officially in a couple of days.

USA Today said the U.S. delegation would include Sig Hecker, director of the Los Alamos National Laboratory from 1985 to 1997. The laboratory produced the first U.S. nuclear bomb. The delegation would also include a China expert from Stanford University, two Senate foreign policy aides who have previously visited Pyongyang and a former State Department official who has negotiated with North Korea.