The Chinese president on Monday assured leaders from the 10-country Association of Southeast Asian Nations (ASEAN) that his country would not "bully" smaller neighbors.
Xi's comments come amid a spike in tensions over the South China Sea, where Beijing's territorial claims overlap many ASEAN members.
The remarks came at a virtual summit held to mark the 30th anniversary of relations between China and ASEAN.
What did the maritime rivals say?
Xi told national leaders that China, which is not an ASEAN member, would never use its size to seek dominance over regional neighbors.
"China resolutely opposes hegemonism and power politics, wishes to maintain friendly relations with its neighbors and jointly nurture lasting peace in the region and absolutely will not seek hegemony or even less, bully the small," Xi said.
The Chinese president said peace was the "greatest common interest" on all sides.
"We must practice true multilateralism and insist on handling international and regional matters through negotiation," Xi said.
The comments came days after Chinese coast guard vessels sprayed a powerful jet of water at Philippine boats carrying supplies to troops on a South China Sea atoll.
In the conference, Philippine President Rodrigo Duterte highlighted the incident at the atoll — known as the Second Thomas Shoal or Ayungin Shoal — part of the Spratly Islands group.
"We abhor the recent event in the Ayungin Shoal and view with grave concern other similar developments," Duterte said, according to a statement from his office.
"This does not speak well of the relations between our nations and our partnership."
The Philippines redeployed the two supply boats to provide food to the marines, who are aboard a World War II-era warship. Manila deliberately ran the vessel aground in 1999, hoping to strengthen its claim to the shoal.
Chinese boats have surrounded the ship, demanding the Philippines tow it away.
Why is ASEAN discussing this?
While ASEAN and China have been negotiating a code of conduct for dealing with disputes in the South China Sea, the talks have made little progress recently.
Beijing's claims in the South China Sea conflict with those of four members — Malaysia, Vietnam, Brunei, and the Philippines.
China has been seeking to strengthen its presence in the maritime region — where there are crucial shipping routes, fishing grounds, and undersea oil and gas deposits.
It has been criticized for layering sand and concrete onto coral reefs or shoals to build airstrips and port facilities.
The powerful Chinese navy, coastguard, and maritime militia have also moved to stop neighbors from exploiting resources in their own exclusive economic zones.
Beijing also strongly objects to operations by the US and other militaries in the area.
Myanmar doesn't show up
China had been keen for Myanmar to take part in the meeting, but the military-ruled nation was not represented.
A diplomat who had been expected to represent Myanmar did not appear at the virtual meeting after ASEAN excluded the junta's chief Min Aung Hlaing.
The censure against Myanmar came after an ASEAN envoy was prevented from meeting ousted leader Aung San Suu Kyi and other political detainees as part of a proposed dialogue on easing the deadly crisis.
Security forces are alleged to have killed almost 1,200 civilians amid anti-coup protests. The Myanmar government has claimed a lower death toll.
While the coup has triggered widespread international condemnation, China — a regional and economic ally — has declined to criticize the generals that presided over it.
Myanmar, a former British colony then known as Burma, was under military rule for decades following a 1962 coup. While Suu Kyi's five years as the nation's effective leader represented a brief period of relative democracy, the country's authorities continued to apply repressive colonial-era laws and engage in ethnic conflict.
rc/msh (Reuters, AFP, dpa, AP)