Washington: US President Barack Obama condemned the North Korean nuclear test that was conducted Tuesday, calling it "highly provocative".
The test, which North Korea claimed was successful, was carried out at 11.57 a.m. in Kilju county, North Hamkyung province, reported Xinhua.
"This is a highly provocative act that, following its December 12 ballistic missile launch, undermines regional stability, violates North Korea's obligations under numerous United Nations Security Council resolutions," Obama said in a statement issued by the White House.
Obama said North Korea's latest move contravenes its commitments under the Sep 19, 2005 Joint Statement of the Six-Party Talks on North Korea's nuclear programmes and "increases the risk of proliferation".
Calling North Korea's nuclear weapons and ballistic missile programs as a threat to US national security and to international peace and security, Obama said the US "remains vigilant in the face of North Korean provocations and steadfast in our defense commitments to allies in the region".