Updated

The U.N. Security Council is strongly condemning North Korea's nuclear test and pledging further action.

A press statement approved by all 15 council members at an emergency meeting Tuesday morning says the test poses "a clear threat to international peace and security."

The council points out that in a resolution it approved unanimously last month stepping up sanctions for North Korea's missile test in December it promised to take "significant action" in the event of a new nuclear test.

"In line with this commitment and the gravity of this violation, the members of the Security Council will begin work immediately on appropriate measures in a Security Council resolution," the council says.