The American President offered to help resolve territorial disputes in the South China Sea during a meeting with his Vietnamese counterpart in Hanoi.

“I am a very good mediator and a very good arbitrator,” Trump said on Sunday ahead of a bilateral meeting with Vietnamese President Tran Dai Quang. “If I can be of help in any way let me know,” he added.

It was unclear if the offhand remark would potentially signal a more proactive U.S. role in finding a solution to one of Asia’s biggest flashpoints. While the U.S. doesn’t take a position on territorial disputes, it has criticised China for land reclamation in the seas and has called for multilateral talks between claimants.

Asked later about Trump’s offer at a joint press briefing in Hanoi, Quang demurred.

“I have shared my thoughts with President Donald Trump on the recent developments in this area,” he said, adding that Vietnam wanted to settle disputes through “peaceful negotiations” in accordance with international law.

China claims more than 80 percent of the South China Sea, where it has constructed features on seven rocks and reefs and installed military facilities. Several Southeast Asian nations and Taiwan also claim parts of the area, through which more than $5 trillion of trade passes each year. China opposes U.S. involvement in resolving the disputes, preferring to settle them through one-on-one talks with claimants.

—Bloomberg