US warns against 'provocation' after North Korea confirms reactor

Pyongyang's confirmation came hard on the heels of suggestions by the chief of the national space agency of a possible satellite rocket launch next month

The United States today urged North Korea to refrain from "irresponsible provocation" after the communist state confirmed the restarting of a nuclear reactor seen as its main source of weapons-grade plutonium.

Pyongyang's confirmation, by the head of the North's Atomic Energy Institute (AEI), came hard on the heels of suggestions by the chief of the national space agency of a possible satellite rocket launch next month.

White House spokesman Josh Earnest said, "North Korea should refrain from irresponsible provocation that serve only to aggravate regional tensions."

He added Pyongyang should "refrain from actions and rhetoric that threaten regional peace and security" and instead "focus instead on fulfilling its international obligations and commitments".

The US intervention came as analysts saw the North Korean moves as aimed at raising tensions in order to place North Korea firmly on the agenda of an expected US-China summit later this month.

In an interview with the North's official KCNA news agency, the director of the AEI, who was not named, said all facilities at the Yongbyon nuclear complex -- including the five-megawatt reactor -- had "started normal operations".

North Korea mothballed the Yongbyon reactor in 2007 under a six-nation aid-for-disarmament accord, but began renovating it after its last nuclear test in 2013.

When fully operational, the reactor is capable of producing around six kilos (13 pounds) of plutonium a year -- enough for one nuclear bomb, experts say.

The AEI director said scientists had been "steadily improving" both the quality and quantity of the North's nuclear deterrent and he issued a by-now standard warning to the United States.

"If the US and other hostile forces persistently seek their reckless hostile policy ... (North Korea) is fully ready to cope with them with nuclear weapons any time," he said.

The warning followed strong hints from Pyongyang that it is considering a satellite rocket launch to mark the 70th anniversary of the founding of the ruling Workers' Party of Korea (WPK) on October 10.

"The world will clearly see a series of satellites... soaring into the sky at the times and locations determined by the WPK central committee," the director of the North's National Aerospace Development Administration said yesterday.

The North insists its rocket launches are intended to put peaceful satellites into orbit. The United States and its allies see them as disguised ballistic missile tests.

North Korea's main diplomatic ally China has protected it from tougher sanctions over its nuclear and missile tests, but is seen as increasingly impatient with its provocative behaviour.