VIENTIANE, Laos — President Barack Obama said Thursday that the United States and Southeast Asian nations gathered in Laos have advanced a vision of an open, dynamic and competitive economic system in which all nations play by the same rules.

President Barack Obama glances at other leaders Thursday at the 11th East Asia Summit on the last day of the 28th and 29th ASEAN Summits in Vientiane, Laos. Bullit Marquez/Associated Press

Obama, closing out the first U.S. presidential visit to Laos, also said he planned to do everything possible to persuade the U.S. Congress to ratify the Trans-Pacific Partnership free trade deal before the end of the year.

Obama leaves office in January. He said that in recent years, the U.S. and Asia had solidified “unprecedented” cooperation that will create more prosperity for their peoples.

“When I think back to the time I spent here as a boy, I can’t help but be struck by the extraordinary progress that’s been made by the region in the decades since, even if there’s still a lot of work to be done,” Obama said.

The president pointed to discussions with Southeast Asian leaders about maritime disputes in the South China Sea and suggested progress had been made in clarifying the path ahead to lower tensions between China and the Philippines. He said the leaders had helped create a unified voice against North Korea in the wake of missile launches that stirred further concerns about the North’s nuclear program.

Obama’s remarks came at the end of a grueling nine-day trip that took the him to Laos and China following U.S. stops in Nevada, Hawaii and Midway Atoll, a U.S.-controlled coral reef in the Pacific Ocean.

At the top of the agenda for Obama’s meetings with Asian leaders in Laos were persistent concerns about China’s behavior in the South China Sea. In a joint statement issued by leaders of the Association of Southeast Asian Nations, members were expected to issue a mild rebuke to China without referencing it by name.

“I realize this raises tensions,” Obama said as he met with ASEAN leader, referring to a recent international arbitration ruling against China on the maritime dispute. “But I also look forward to discussing how we can constructively move forward together to lower tensions and promote diplomacy and regional stability.”

On his last day in Asia, Obama met with Indian Prime Minister Narendra Modi, whose help Obama is seeking to galvanize further action on climate change, especially among developing countries. The two grinned and shook hands but made no substantive comments as reporters were allowed in briefly for the start of their meeting.

Obama’s final stop in Laos included an informal conversation with Philippine President Rodrigo Duterte on the sidelines of a summit. Obama had canceled a formal meeting with Duterte after the new Philippine leader used a crude schoolyard epithet to insult the president and warn him not to bring up extrajudicial killings in the Philippines during their meeting.