The USA Today newspaper reported the visit to Yongbyong, scheduled for 6-10 January, had been approved by the administration of US President George Bush.
And South Korea confirmed the deal on Friday, raising hopes in Seoul of a breakthrough in a long-running nuclear dispute.
"The report is true, but we don't know what the US delegation will do in North Korea," an South Korean official said.
The first foreigners to visit North Korea's nuclear facilities since the communist state expelled UN inspectors a year ago, the US delegation includes a top nuclear scientist and a China expert from Stanford University.
It also includes two US Senate foreign police aides and a former State Department official who has negotiated with Pyongyang.
According to USA Today, the nuclear scientist on the delegation is Sig Hecker, who from 1985-1997 directed the Los Alamos National Laboratory where the atomic bomb was first developed.
The news follows North Korea's recent announcement that it is ready to join delayed six-nation talks on the crisis sparked by its drive for nuclear weapons in October 2002.
Yonhap news agency in Seoul quoted an unidentified South Korean government official as saying the North Korean move could mark a turning point in the standoff.
"This is a strong signal from North Korea that it has no intention to escalate the crisis any further," he said.
"Consistent is our principled stand to seek a negotiated peaceful solution to the nuclear issue... But we will always react with the toughest policy to the US hardline policy of totally denying and threatening the dignified idea and system of our style"
North Korean statement
While vowing to continue its diplomatic arm-wrestling with the United States, Pyongyang said in a New Year message that it was ready to peacefully resolve its nuclear crisis.
"Consistent is our principled stand to seek a negotiated peaceful solution to the nuclear issue between the DPRK (North Korea) and the US.
"But we will always react with the toughest policy to the US hardline policy of totally denying and threatening the dignified idea and system of our style."
The North Koreans added they would take the "toughest" measures unless Washington changed its stance towards Pyongyang.
The first round of six-way talks ended inconclusively in Beijing in August, with North Korea later dismissing the negotiations as "useless".
The second round had been expected in Beijing this month but was pushed back due to differences over the steps needed towards a settlement.
Washington has demanded that Pyongyang unilaterally scrap its nuclear programme, but North Korea has insisted on a legally binding security guarantee from the United States in return for a nuclear climbdown.