A united U.N. Security Council strongly condemned North Korea's nuclear test and pledged further action Tuesday, calling Pyongyang's latest defiant act "a clear threat to international peace and security.", AP reported. A press statement approved by all 15 council members at an emergency meeting hours after the latest underground test called the atomic blast a "grave violation" of three U.N. resolutions banning the North from conducting nuclear or missile tests. North Korea conducted nuclear weapons tests weeks after rocket launches in 2006 and 2009, and this third test followed a rocket launch in December. The Security Council pointed out that in a resolution it approved unanimously last month, which strengthened sanctions in response to the December missile test, members 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 said. The statement was read by South Korea Foreign Minister Kim Sung-hwan, whose country holds the rotating Security Council presidency this month. South Korea was elected to the council for a two-year term starting in January. "North Korea will be held responsible for any consequences of this provocative act," he told reporters. U.S. Ambassador Susan Rice called the test "highly provocative" and said the North's continued work on its nuclear and missile programs threatens regional and international peace and security and "the security of a number of countries including the United States." "They will not be tolerated," she said, "and they will be met with North Korea's increasing isolation and pressure under United Nations sanctions." Rice said "the U.N. Security Council must and will deliver a swift, credible and strong response by way of a Security Council resolution that further impedes the growth of DPRK's nuclear weapons and ballistic missile programs and its ability to engage in proliferation activity." Rice said there are a number of further measures that will be discussed in coming days with council members and concerned states that will not only tighten existing measures but augment the sanctions regime. She added in response to a question that financial sanctions and sanctions on financial institutions are areas "that we think are right for appropriate further action."