North Korea has declared a major advance in its nuclear program a week after launching a deadly artillery strike on a South Korean island.
North Korean state media said Tuesday the country has a new uranium enrichment plant with thousands of working centrifuges and a light-water reactor that is currently under construction. They said both facilities are designed for peaceful energy use.
North Korea first disclosed the projects to a visiting American scientist earlier this month. Experts say the uranium enrichment plant could be another vehicle for North Korea to make nuclear weapons in addition to its known plutonium-based weapons program.
North Korea's claims about the new facilities could not be independently verified.
Pyongyang motives unclear
Some analysts say North Korea's nuclear revelations and shelling of Yeonpyeong island are designed to pressure the United States and its allies into resuming talks on providing aid to Pyongyang in return for the scrapping of its nuclear weapons program.
U.S. and South Korean warships held a third day of naval drills in the Yellow Sea Tuesday in a show of strength to deter North Korean attacks.
North Korea shelled Yeonpyeong last Tuesday, killing four South Koreans on an island near the disputed western maritime boundary of the two Koreas.
Pyongyang said it was retaliating for a South Korean exercise that involved artillery fire from the island into surrounding waters that it claims are North Korean. South Korean forces responded within minutes to North Korea's attack by shelling North Korean positions across the maritime border.
Both Koreas have warned of severe retaliation for future attacks by the other side.
China proposes emergency talks
The foreign ministers of the United States, Japan and South Korea plan to meet in Washington next week to consider a response to North Korea's recent actions.
China has urged the three allies to agree to its proposal for an emergency meeting next month in Beijing of all six nations involved in North Korean nuclear negotiations. The talks also would involve North Korea, China and Russia.
Japanese Foreign Minister Seiji Maehara said Tuesday North Korea must make progress in implementing previous agreements to end its nuclear weapons program before more six-party talks are held.
He said he instructed Japanese envoy Akitaka Saiki to deliver that message to China during talks Saiki held with Chinese envoy Wu Dawei in Beijing Tuesday. Kyodo quotes Saiki as telling Wu that Japan believes it is not appropriate to hold a six-party meeting at the present time.
WikiLeaks reveal Beijing's frustrations
U.S. diplomatic cables leaked this week by the website WikiLeaks suggest China is frustrated by North Korea's behavior and would not intervene if that country's leadership collapses.
In one cable, U.S. Ambassador to Seoul Kathleen Stephens says South Korea's then-vice foreign minister Chun Yung-woo told her that China will accept a re-unified Korea provided that such a state is in a "benign alliance" with Washington and is not hostile to Beijing.
The cable, which dates from last February, also quotes Chun as saying China would not accept the presence of U.S. troops north of the demilitarized zone that currently divides the Korean peninsula.
In a separate cable dated June 2009, U.S. Ambassador to Kazakhstan Richard Hoagland quotes a Chinese envoy as telling him that Beijing is "genuinely concerned" by North Korean nuclear missile tests. The Chinese envoy also is quoted as saying the tests are a "threat to the whole world's security."