The leaders of the United States and the Association of Southeast Asian Nations will elevate their relationship to a "comprehensive strategic partnership" later this year amid China's growing clout in the region.
China has preceded the United States in upgrading its relations with the 10-member group to a similar status, and the latest development reflects intensifying competition between Beijing and Washington for influence in the fast-growing Southeast Asian region.
US President Joe Biden said at the US-Asean Special Summit in Washington, DC, "We're launching a new era in US-Asean relations", while welcoming the 45th anniversary of their ties this year.
Placing an emphasis on Asean is the "very heart" of US strategy to achieve a free, open and prosperous Indo-Pacific, Mr Biden said, alluding to the strategically important region straddling key sea lanes including the South China Sea where Beijing is making extensive territorial claims.
It was the first time the United States has hosted Asean leaders in the capital. A joint statement issued afterwards said, "We commit to establish an Asean-US Comprehensive Strategic Partnership that is meaningful, substantive, and mutually beneficial at the 10th Asean-US Summit in November 2022."
To show its commitment to Asean, the Biden administration pledged over US$150 million (5.2 billion baht) of investment for maritime security, infrastructure and other initiatives.
The administration is also hoping to launch the Indo-Pacific Economic Framework, a regional engagement initiative that it proposed in the fall amid the United States' absence from major free-trade agreements in the region.
The joint statement said the United States and Asean will focus on stronger and inclusive economic growth, such as through "the vital economic participation" of the US in the region.
They also called for the "immediate cessation of violence" in Myanmar following its military coup last year, and vowed to redouble efforts toward "a peaceful solution".
As Mr Biden rallies countries to support Ukraine in its fight against Russia, the joint statement called for "respect for sovereignty, political independence, and territorial integrity".
Speaking after Friday's summit session, Prime Minister Prayut Chan-o-cha said he urged the US and all Asean leaders to drop their determination to compete and win against one another and focus more on the humanitarian aspects of not only the war but other issues as well.
"As for its role in the region, Thailand will concentrate on defusing conflicts and preventing confrontation.
"We are willing to fully collaborate with every country in working toward the recovery of the economy and to ensure peace and security," he said.
In his speech at the meeting, Gen Prayut pointed to the need for Asean and the US to focus on building security, economic and climate frameworks.
Asean will need a strong mechanism to build trust among its members before an ideal security landscape can be built to facilitate the region's economic recovery and sustainable growth, he said.
New digital technology and strong supply chains will become driving forces in building a better economic landscape, he added.