By Josh Smith
SEOUL, Dec 1 (Reuters) - The United States is working a new round of sanctions against North Korea, U.S. National Security Advisor Jake Sullivan said on Thursday, as Pyongyang forges ahead with banned missile development and signals a possible new nuclear test.
"We have a new set of sanctions measures coming forward as we speak," he told a conference in Seoul organised by the U.S.-based Center for Strategic and International Studies and the South Korean JoongAng media group.
Sullivan, who spoke via live video link, did not elaborate but said Washington was committed to using pressure and diplomacy to entice North Korea into giving up its nuclear arsenal.
The "North Star" of U.S. Joe Biden's North Korea policy is the denuclearisation of the Korean peninsula, and it remains steadfast in pursuing that goal while being flexible in working with partners on how to achieve it, he said.
He pointed to increased cooperation between the United States, South Korea, and Japan, which have increased joint military drills. The United States is also working on a more "visible" regional presence of its strategic assets, Sullivan said, referring to major weapons such as aircraft carriers and long-range bombers.
North Korea has said denuclearisation is off the table, and accused the United States and its allies of pursing "hostile" policies, including sanctions, that have left it no choice but to expand its military.
Sullivan said Washington had no ill intent toward North Korea and is open to talks without preconditions.
"Pyongyang has rejected this sincere outreach," he said.
The last round of U.S. sanctions in October targeted two Singapore-registered companies and a Marshall Islands-registered firm that Washington said support Pyongyang's weapons programmes and its military.
Decades of U.S.-led sanctions have not halted North Korea's increasingly sophisticated missile and nuclear weapon programmes, and China and Russia have blocked recent efforts to impose more United Nations sanctions, saying they should instead be eased to jumpstart talks and avoid humanitarian harm.
Sullivan said the administration has no illusions about the challenges, but that the United States remained committed to holding North Korea accountable. (Reporting by Josh Smith. Editing by Gerry Doyle)