Trade, terrorism and the South China Sea territorial disputes are set to top the agenda for the Asean leaders converging on the Sunnylands estate in California today for the first-of-its-kind summit with United States President Barack Obama.
Prime Minister Lee Hsien Loong, who is on a week-long visit to the US, will attend the summit along with his counterparts from the other Asean states. Myanmar's President Thein Sein will not be attending.
This is the first time the US is hosting a meeting with Asean's leaders.
While there are no concrete agreements expected out of the summit, it is still considered a critical forum.
The US State Department's top diplomat to Asia Danny Russel told foreign journalists last week that the summit will take on a different tone from the annual meetings the two sides have as part of the annual Asean summits in Asia.
"It is not a laboriously negotiated, strict, by-the-Roman-numerals agenda; it is an open discussion among the leaders," he said. "It also means that the leaders aren't wedded to the traditional or the conventional formats when it comes to communiques and outcomes and deliverables and so on. They have some latitude. It's a personal engagement and it's built on the personal relationships that have been forged over the last seven-plus years."
Mr Russel and others have also stressed the symbolic importance of the meeting, saying it was a marker of just how much weight the Obama administration has placed on South-east Asia.
Said Mr Daniel Kritenbrink, National Security Council senior director for Asian affairs: "The Sunnylands summit represents our commitment to the President's rebalance strategy to the Asia-Pacific... The region's dynamism presents the United States with both extraordinary opportunities and challenges, and that's why from the beginning the President has prioritised engagement with the region, and that is why he is hosting this summit."
In terms of substance, recent developments have ensured that the leaders will have much to tackle.
On trade, the Trans-Pacific Partnership free trade deal, which includes the US and four Asean nations, will likely draw attention as observers look for indications of the likelihood that it will pass the US Congress. The deal, signed by 12 countries, is up for ratification by their legislatures. In the US, the issue is complicated by election-year politics. Thus far, nearly every candidate on both sides of the aisle has voiced opposition to the deal, saying that it hurt American jobs.
On terrorism, Washington pundits said the White House will want to engage states like Malaysia and Indonesia as it sees both as critical allies for stopping radicalisation.
Dr Patrick Cronin of the Centre for a New American Security said he would be looking for the meeting to go beyond the normal statements of concern in joint communiques.
"I don't think there's much disagreement in Asean about this (countering terrorism). So I expect there to be some words to this effect. But I think more important than those words is really what we are going to be doing, going forward, with Indonesia and Malaysia and other countries and what Asean can do," he said.
The ongoing threat of militant group Islamic State in Iraq and Syria as well as the recent attacks in Jakarta have increased the urgency of the situation.
As for the territorial disputes, Mr Obama is expected to make strong remarks warning China against "bullying" others.
Said Mr Ben Rhodes, US Deputy National Security Adviser for Strategic Communications: "We will continue to underscore the principle that these issues have to be resolved consistent with international norms and not through bigger nations bullying smaller ones."
