WASHINGTON - North Korea has made good on threats to restart its nuclear program, carrying out a nuclear test with an explosion similar to the of the bombs that flattened Hiroshima and Nagasaki in WWII.

In a one-two punch, the rogue regime announced it successfully conducted an underground nuclear test. It followed up by firing three short range missiles - a move Pyongyang says will help to bolster its self-defense.

But critics say it only increases tensions with neighbors and strains relations with the international community.

"It is now very clear that North Korea is basically intent on becoming a nuclear state," Lee Jung-Hoon, professor of International Security at Yonsei University.

The White House condemned the declaration as a "blatant act of defiance" and "a matter of grave concern to all nations." The United Nations has called an emergency meeting in the wake of the tests.

North Korea has been sounding a retaliatory tone since it received push back for a rocket launch last month.

The communist regime has also been looking for aid. Experts see this nuclear test as a way to get the attention of the Obama administration, and gain the upper hand in future negotiations with the United States.