US says 'extremely engaged' in Asia after Trump skips ASEAN meet

US Commerce Secretary Wilbur Ross insisted Monday that his country remained "extremely engaged" with Asia despite Donald Trump skipping a regional leaders summit.

Ross and US national security advisor Robert O'Brien are the most senior members of the Washington delegation in Bangkok for the Association of Southeast Asian Nations (ASEAN) meeting, also attended by Indian, South Korean and Japanese leaders.

Previous meetings have been attended by the president or vice president. Trump is accused of retreating from the region after pulling out of a major Asia-Pacific trade pact almost immediately after taking office.

But Ross pushed back against criticism that America has turned its back on Asian allies.

"The Trump administration is extremely engaged in and fully committed to this region," he said at a business forum on the sidelines of the ASEAN meeting Monday.

"We continue to negotiate trade deals with countries in this region." At the US-ASEAN meeting later in the day, O'Brien addressed several Southeast Asian foreign ministers after some leaders failed to turn up.

Only the leaders of Thailand, Vietnam and Laos were in attendance, a departure from earlier ASEAN meetings over the weekend that heads-of-state were present for.

Trump has railed against countries in Asia for building massive trade surpluses with the US and has vowed to pursue bilateral deals in the region in favour of sprawling pacts.

He signed a free trade agreement with Japan earlier this year and also renegotiated the terms of a trade deal with South Korea.

Soon after he took office Trump pulled out of the Trans-Pacific Partnership (TPP) -- which would have been the world's biggest free trade pact -- calling the deal a "job killer".

It has since been reborn as a watered down deal without the US, and another China-backed trade pact is now set to be the world's largest when it is signed.

The 16-nation Regional Comprehensive Economic Partnership (RCEP), which could be finalised next year, includes 30 percent of global GDP and half of the world's people. It includes all 10 ASEAN states plus China, India, Japan, South Korea, Australia and New Zealand -- notably excluding the US.

Washington remains locked in its bruising trade war with China, with both slides slapping tit-for-tat tariffs on billions of dollars worth of goods.

Ross said an agreement to row back some of those tariffs was "very far along". Trump has said the deal could be soon signed with Chinese leader Xi Jinping, possibly in the US state of Iowa.

Trump attended the ASEAN summit in the Philippines in 2017 while Vice President Mike Pence appeared last year.

A senior White House official denied that Washington had snubbed this year's event, saying Trump and Pence are unavailable because they are "very engaged in campaigning" for a string of governors' races.