Singapore on Saturday urged the United States to remain engaged with Southeast Asia, following the announcement U.S. President Donald Trump will skip a major regional conference and send Mike Pence instead.

The White House announcement that Trump will not attend the Association of Southeast Asian Nations' summit in November was a particular disappointment to Singapore, which will host and chair the conference.

Expectations were high that Trump would attend the ASEAN Summit -- in a gesture of goodwill if nothing else -- after Singapore provided the venue for Trump's historic summit with North Korean leader Kim Jong Un in June, at a cost to the Singapore government of S$16.3 million (US$12 million).

However, concern has intensified around Southeast Asia that U.S. interest in the region is waning under Trump, who withdrew the United States from the Trans-Pacific Partnership free trade deal soon after taking office.

The United States is ASEAN's third-largest trading partner and fourth-largest source of foreign direct investment.

"We look forward to the United States' continued...engagement in the region as we take meaningful strides towards the next step of our cooperation," Singapore Trade and Industry Minister Chan Chun Sing said in a speech Saturday at the start of an annual meeting of ASEAN and U.S. trade ministers in Singapore.

The United States sent Deputy U.S. Trade Representative Jeffrey Gerrish to Saturday's meeting. Last year's meeting in Pasay City in the Philippines was attended by Assistant U.S. Trade Representative Barbara Weisel.

In his opening remarks, Gerrish reiterated the continued importance of ASEAN to the United States and its deep and lasting commitment to the region.

"As the 10 countries of ASEAN continue to grow...and ASEAN integration continues to deepen, ASEAN is becoming a much more important trading partner of the U.S.," Gerrish said.

Chan said that on the economic front, trade and investment relations between the United States and ASEAN "remain strong" and both sides have been exploring new areas of cooperation such as in the area of agricultural biotechnology.

ASEAN groups Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, the Philippines, Singapore, Thailand and Vietnam.