2nd N Korea nuke test suspected
Washington - The US intelligence chief said on Monday that a scientific analysis has concluded that North Korea "probably" carried out a second nuclear test in May with a yield of "a few kilotons".
Director of National Intelligence Dennis Blair announced the finding in a statement issued amid concerns that North Korea may be preparing for yet another nuclear test.
"The US intelligence community assesses that North Korea probably conducted an underground nuclear explosion in the vicinity of P'unggye on May 25, 2009. The explosion yield was approximately a few kilotons," Blair said.
An estimate by Russia's defence ministry at the end of May put the estimated yield of the underground explosion at 10 to 20 kilotons.
South Korean President Lee Myung-Bak, meanwhile, arrived on Monday in Washington for talks on Tuesday with President Barack Obama about North Korea, which also recently tested a long range missile.
UN tightening sanctions
The UN Security Council unanimously decided on Friday to tighten financial and other sanctions in response to the May 25 nuclear test, North Korea's second since October 2006.
Pyongyang reacted on Saturday with defiant vows to build more bombs and to start on a new weapons programme based on uranium enrichment.
It was the first time that Pyongyang had said it would pursue a uranium enrichment programme, having previously denied US charges that it had a clandestine programme to enrich uranium for nuclear weapons.
US intelligence officials have warned Obama that North Korea will conduct another nuclear test in response to the toughened sanctions, according to US media reports last week, citing intelligence sources.