The US-led regional forum in the Indo-Pacific, known as the Quad, may serve as the foundation of US foreign policy in the region, the top US security adviser said Friday.

National Security Adviser Jake Sullivan also said the Joe Biden administration will continue to build on the Quad.

"I think we really want to carry forward and build on that format, that mechanism which we see as a foundation upon which to build substantial American policy in the Indo-Pacific region," Sullivan said at a virtual event, also attended by his immediate predecessor, Robert O'Brien.

The event, named "Passing the Baton," was hosted by the US Institute of Peace, which said it has hosted similar events involving top national security officials from new and former administrations at each change of administration over the past 20 years.

O'Brien said the new administration will have to work with "all means of national power" and "certainly allies and friends" in dealing with challenges posed by China.

"I am glad to see that, I think, as we work together with our allies, especially with the quad -- Japan, Australia, India and the United States, which may be the most important relationship we have established since NATO at a high level -- I think we are gonna be able to confront that challenge," said O'Brien.

Sullivan said the new administration will continue to work with the multilateral forum in the Indo-Pacific and also reinforce it.

"I think you will see continuity and an effort to reinforce...carry forward steps that had been taken by the previous administration," he told the online event.

The Trump administration had sought to expand the regional forum into a "Quad Plus," arguing it could be a NATO-like alliance to counter what it called growing aggression from China's communist party.

The tension between the US and China had placed much pressure on US allies in Asia, where, for many, including South Korea, China's economic presence easily overwhelms that of any others.

Sullivan stressed the need to work with allies, partly to impose costs on China for its actions.

"We represent well more than half of the world's economy, and that provides us, not just the kind of leverage we need to be able to produce outcomes, but it provides us a chorus of voices that can drive the argument that says, 'We are going to stand up for a certain set of principles in the face of aggression and the kinds of steps that China has taken'," he said.

"The last piece is speaking with clarity and consistency on these issues and being prepared to act, as well to impose costs for what China is doing in Xinjiang, what it's doing in Hong Kong, for the bellicosity and threats that it is projecting towards Taiwan," added the White House official. (Yonhap)