ADDIS ABABA, Rabi'II 14, 1437, January 24, 2016, SPA -- The United States is not close to an agreement with China on new United Nations Security Council measures to impose on North Korea over its fourth nuclear test earlier this month, said U.S. Ambassador to the United Nations, Samantha Power, on Saturday, according to Reuters. North Korea said on Jan. 6 that it successfully tested a powerful nuclear bomb. Nuclear experts say North Korea likely gained data and practical know-how from the test. They reject North Korea's assertion that it detonated a hydrogen bomb. The 15-member U.N. Security Council said at the time it would begin working immediately on significant new measures in response to North Korea, a threat diplomats said could mean an expansion of sanctions. Since then diplomats said Washington and Beijing have been primarily negotiating on a draft resolution in consultation with Britain, France, Japan, South Korea and Russia. When asked on Saturday if the United States and China were nearing agreement, Power said: "No." She did not elaborate. Power was in Addis Ababa after a brief visit to Burundi with the U.N. Security Council. North Korea has been under Security Council sanctions since it first tested an atomic device in 2006. After a nuclear test in 2013, the Security Council took about three weeks to agree a resolution that tightened financial restrictions and cracked down on Pyongyang's attempts to ship and receive banned cargo. Several U.N. diplomats said that veto-power Russia, not China, may prove to be a greater obstacle to expanding existing sanctions against North Korea. Moscow is itself under U.S. and European Union sanctions over its annexation of Crimea and support for pro-Russian rebels in eastern Ukraine. A U.S. official, speaking on condition of anonymity, said consultations continued with council members and interested parties "on a tough, comprehensive, and credible package of new sanctions on North Korea for this latest provocation." "We're moving as quickly as possible," the official said on Monday. A senior U.N. diplomat said some council members wanted a resolution "that really does mark a shift in the way that we respond to what happened." He said the aim was "to show that we have recognized that North Korea has upped the ante and that the council is intent on denuclearization in North Korea." The diplomat, speaking on condition of anonymity, described the work by the United States as "careful, thorough and deliberate way." --SPA 00:46 LOCAL TIME 21:46 GMT www.spa.gov.sa/w