North Korean claims to have a working uranium enrichment program are provocative and disappointing but "not a crisis", says the visiting US special envoy to the communist state.
Stephen Bosworth's comments on Monday followed disclosures during the weekend by a US scientist that he had toured a new uranium enrichment plant in the North, raising the prospect that Pyongyang is preparing to build a more powerful atomic bomb.
Stanford University professor Siegfried Hecker, in an interview with The New York Times, said he saw "hundreds and hundreds" of centrifuges and was "stunned" by the plant's sophistication.
Advertisement: Story continues below Hecker said the North Koreans told him 2000 centrifuges were running, but he could not verify claims that the plant at the Yongbyon complex was already producing low-enriched uranium.
Bosworth termed the announcement disappointing and "another in a series of provocative moves" by the North.
"That being said, this is not a crisis," he said, after talks with South Korean Foreign Minister Kim Sung-Hwan and ahead of visits to Japan and China.
"We are not surprised by this. We have been watching and analysing the (North's) aspirations to produce enriched uranium for some time. It goes back several years."
The US envoy said the program violated a United Nations resolution and a September 2005 six-nation agreement, under which the North agreed to scrap its nuclear programs in return for aid and diplomatic and security benefits.
