COUNTRIES claiming parts of the South China Sea should assert their rights and act collectively to set China on the right path, United States Defense Secretary Mark Esper said yesterday.

“Acting collectively is the best way to send that message and to get China on the right path,” Mr. Esper told a televised briefing in Manila after meeting with his Philippine counterpart.

The US is also concerned about China’s “excessive claims” in the region and its “lack of compliance with international law,” he said.

China claims more than 80% of the oil-rich waters of the South China Sea, where it has set up military outposts on reclaimed islands. The Philippines, Brunei, Malaysia, Taiwan and Vietnam also claim parts of the sea.

China on Monday called on the US military to stop flexing its muscles in the disputed waterway and to avoid adding new uncertainties over Taiwan, Chinese spokesman Wu Qian said, recounting the remarks by Chinese Defense Minister Wei Fenghe to Mr. Esper during high-level talks on the sidelines of a gathering of defense ministers in Bangkok.

The remarks came two weeks after a top White House official denounced Chinese “intimidation” in the busy waterway. It also came a day after Mr. Esper accused China of “increasingly resorting to coercion and intimidation to advance its strategic objectives” in the region.

“Mr. Esper’s visit is a signal that the US will not go away as a reliable ally especially after President Donald Trump’s absence at this year’s Asean summits in Bangkok, which created space for China,” Ramon C. Casiple, executive director of the Institute for Political and Electoral Reform, said by telephone.

“But the US has to do more because a collective action by claimant countries is still no match to China in terms of military, political, diplomatic and economic clout,” the political analyst said. “In all our foreign relations, China is the elephant in the room.”

At yesterday’s briefing, Mr. Esper also said South Korea can and should contribute more on cost-sharing for hosting the US military, after Seoul broke off the talks earlier in the day following a public backlash.

“South Korea is a wealthy country,” he said. “They can and should contribute more. And beyond that I will leave it to the State Department to work out the particulars.”

He declined to say what the US would do when asked if he was willing to withdraw American forces if an agreement was not reached. He added that the US State Department was leading the talks.

“I’m sure it’s in capable hands,” Mr. Esper said, referring to US negotiations with South Korea.

At their meeting yesterday, Mr. Esper and Philippine Defense Secretary Delfin N. Lorenzana agreed to boost defense cooperation, the US Embassy in Manila said in an emailed statement.

The Defense chiefs agreed to deepen defense cooperation “by reinforcing respective national defense capabilities and interoperability, enhancing joint military exercises, disaster response initiatives, and cybersecurity awareness, and improving defense infrastructure through the Enhanced Defense Cooperation Agreement,” it said.

Both secretaries had also reiterated the Mutual Defense Treaty’s applicability to the entire Pacific region, including the South China Sea, the US Embassy said. The two discussed proposals “to support the United States’ efforts to help modernize the Armed Forces of the Philippines, improve maritime security capabilities and domain awareness, and provide rapid humanitarian assistance.”

The Philippines and US reiterated their commitment to uphold freedom of navigation, and overflight in the South China Sea. The two nations also stressed the importance of “peacefully resolving disputes in accordance with international law,” according to the embassy statement. — Norman P. Aquino