The Government has strongly condemned the testing of nuclear weapons in North Korea this morning and called on the Democratic Peoples' Republic of Korea (DPRK) to return to the six-party talks.
The Minister for Foreign Affairs, Dermot Ahern, called on the DPRK to stop carrying out any further dangerous acts, which are a threat to regional security.
North Korea boasted this morning it had performed its first-ever nuclear weapons test.
In defiance of world opinion, it said its successful underground blast was a "great leap forward".
"I strongly condemn the provocative decision by the DPRK to test a nuclear weapon," said Mr Ahern. "This is a threat to regional security and in direct contravention of the objectives of nuclear disarmament and non-proliferation.
"It runs directly contrary to the will of the international community, as expressed by the UN Security Council, and it also ignores the patient efforts of the DPRK's neighbours to work constructively with it.
"I call on the DPRK to refrain from further dangerous acts and to return immediately and without preconditions to the Six Party Talks."