Breaking News . Korea Nuclear Test .

Reuters) - North Korea conducted its third nuclear test on Tuesday in defiance of existing U.N. resolutions, drawing condemnation from around the world, including from its only major ally, China, which summoned the North Korean ambassador to protest.

The reclusive North said the test was an act of self-defense against "U.S. hostility" and threatened further, stronger steps if necessary.

It said the test had "greater explosive force" than the 2006 and 2009 tests. Its KCNA news agency said it had used a "miniaturized" and lighter nuclear device, indicating that it had again used plutonium which is more suitable for use as a missile warhead.

North Korean leader Kim Jong-un, the third of his line to rule the country, has presided over two long-range rocket launches and a nuclear test during his first year in power, pursuing policies that have propelled his impoverished and malnourished country closer to becoming a nuclear weapons power.

China, which has shown signs of increasing exasperation with the recent bellicose tone of its neighbor, summoned the North Korean ambassador in Beijing and protested sternly, the Foreign Ministry said.

Foreign Minister Yang Jiechi said China was "strongly dissatisfied and resolutely opposed" to the test and urged North Korea to "stop any rhetoric or acts that could worsen situations and return to the right course of dialogue and consultation as soon as possible".

China is a permanent member of the Security Council.

U.S. President Barack Obama labeled the test a "highly provocative act" that hurt regional stability and pressed for new sanctions.

"The danger posed by North Korea's threatening activities warrants further swift and credible action by the international community. The United States will also continue to take steps necessary to defend ourselves and our allies," Obama said in a statement.

Edited by india100 - Feb 12 2013 at 8:13am