Southeast Asian leaders expressed "deep concern" over US tariffs on Tuesday, as they held a summit with China and Gulf states hailed as "a response to the call of the times" in a geopolitically uncertain world.

The trade-dependent economies are looking to insulate themselves after US President Donald Trump blew up global trade norms by announcing a slew of levies targeting countries around the world, then paused most for 90 days.

The Association of Southeast Asian Nations (Asean) released a statement on Tuesday night expressing "deep concern over... the imposition of unilateral tariff measures, which pose complex and multidimensional challenges to Asean's economic growth, stability, and integration".

In another statement, the bloc stressed "our strongest resolve to stand together" in the face of the levies, and pledged to expand cooperation with other partners.

Malaysian premier Anwar Ibrahim further said the leaders had reached an understanding that any bilateral agreements they might strike with the United States on trade tariffs would not harm the economies of fellow members.

"While proceeding with bilateral negotiations ..., the consensus rose to have some sort of understanding with Asean that decisions should not be at the expense of any other country," said Anwar, who on Monday said he had written to Trump requesting an Asean-US meeting on the tariffs.

"So we will have to protect the turf of 650 or 660 million people," he said of Asean.

Earlier in the day Malaysia, which holds the bloc's rotating chairmanship, hosted the inaugural summit between Asean, China and the Gulf Cooperation Council (GCC) – a regional bloc made up of Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates.

Premier Li Qiang told the meeting that "against the backdrop of a volatile international situation", the summit was "a pioneering work of regional economic cooperation".

"This is not only a continuation of the course of history, but also a response to the call of the times," he said.

Later, at a dinner event, Li urged Gulf and Asean countries to remove trade barriers and expand liberalisation in the face of rising protectionism and unilateralism.

"We all need to firmly maintain the multilateral trading system with the World Trade Organization as the core, and promote the creation of a stable and orderly international market environment," he said. (Agencies)