Secretary of State Rex Tillerson said Friday he can envision the US and North Korea agreeing to hold talks at some point as a precursor to formal negotiations.
US President Donald Trump told his Vietnamese counterpart yesterday he is ready to help resolve the dispute in the resource-rich South China Sea, which Beijing claims most of.
Mr Trump's offer comes ahead of Chinese president Xi Jinping's attempt to woo Vietnam on the issue in a state visit.
The summit of Asia-Pacific Economic Cooperation (APEC) countries in Vietnam put on show the contrasting vision of the "America First" policy with the traditional consensus favouring multinational deals that China now seeks to champion. "I'm a very good mediator and arbitrator".
In Hanoi earlier on Sunday, Trump said he was prepared to mediate between claimants to the South China Sea, where four ASEAN countries and Taiwan contest China's sweeping claims to the busy waterway.
"I believe in our intel agencies", he said, alongside Vietnam President Tran Dai Quang.
On Monday, the 31st ASEAN Summit and Related Summits will be officiated by Duterte at the Cultural Centre of the Philippines before the leaders gather at the Philippine International Convention Centre for a series of meetings, including the 40th anniversary of ASEAN-US Dialogue Relations.
"I just wanted to congratulate you because I am hearing of the unbelievable job on the drug problem", Trump said, not mentioning the thousands killed and global scorn.
Since coming to office 16 months ago, the firebrand leader has been conciliatory to Beijing, despite a ruling by an worldwide arbitration court favoring the Philippines in its territorial dispute with China.
The South China Sea dispute will be one of the major issues at the East Asia Summit in The Philippines this week.
His final stop is the Philippines.
In addition to claiming the vast majority of the 1.4 million square miles (3.5 million square kilometers) of sea - China has built-up small islands in the sea and outfitted them with missile systems, much to the chagrin of its Asian neighbors and the United States.
Leaders at the Philippines summit will discuss the South China Sea, but mainly to agree on a procedural step to cool tensions.
The framework seeks to advance a 2002 Declaration of Conduct (DOC) of Parties in the South China Sea.
US Navy ships have also carried out freedom of navigation patrols in the area, angering China, which says the territorial issues should be handled directly between countries in the region.