SEOUL - North Korea has produced more plutonium to make nuclear weapons, official media said Tuesday, a day after the communist state threatened to "go its own way" unless Washington agrees to direct talks.

The country had "successfully completed reprocessing 8,000 spent fuel rods by the end of August" at its Yongbyon nuclear complex, the official Korean Central News Agency (KCNA) said.

"Noticeable successes have been made in turning the extracted plutonium weapon-grade for the purpose of bolstering up the nuclear deterrent," it said.

The comments indicated the North's growing impatience at Washington's delay in accepting an offer of bilateral talks to end the nuclear standoff.

On Monday its foreign ministry pressed the United States to agree to such talks, and said these could lead to a resumption of stalled six-nation nuclear disarmament negotiations.

"If the US is not ready to sit at a negotiating table with the DPRK, it will go its own way," a ministry spokesman added.

Experts believe the 8,000 rods could produce enough plutonium for one or two nuclear bombs, in addition to the North's current stockpile which could perhaps fuel six to eight weapons.

The North quit the six-party talks in April after the United Nations censured its long-range rocket launch, and vowed to restart the nuclear program which it shut down under a 2007 six-party pact.

It conducted an atomic weapons test in May, its second since 2006.

KCNA said the UN censure of what it calls a peaceful satellite launch "was a grave insult to the dignity of its people."

It said it was compelled to bolster "its deterrent for self-defense to cope with the increasing nuclear threat and military provocations of the hostile forces."