The United States opposes any unilateral efforts to change the Taiwan status quo, especially by force, and its policy on Taiwan has not changed, Secretary of State Antony Blinken told Southeast Asian counterparts on Thursday.

Cross-strait stability is in the interests of the whole region, he told a meeting in Cambodia, a day after U.S. house speaker Nancy Pelosi visited Taiwan. It was the highest-level U.S. visit in 25 years, infuriating China, which claims the self-ruled island as part of its territory.

"We and countries around the world believe that escalation serves no one and could have unintended consequences that serve no one's interests, including ASEAN members, and including China," Blinken said.

On Thursday, China fired multiple missiles as it conducted the largest-ever military drills around Taiwan, while Foreign Minister Wang Yi said China had made the utmost diplomatic effort to avert crisis, but would never allow its core interests to be hurt.

Blinken is in Cambodia for a security-focused meeting of more than 27 countries expected to discuss a food crisis caused by the Russia-Ukraine war, stability in the Taiwan Strait, and the crisis in Myanmar.

Blinken and ASEAN pledged during their meeting to upgrade ties to a comprehensive strategic partnership.

He earlier met Qatar's foreign minister to talk about developments in Afghanistan and Iran and discussed Sri Lanka's economic crisis with his Indian counterpart Subrahmanyam Jaishankar.

He later met Sri Lanka's new foreign minister, Ali Sabry and promised support for the country reeling from an economic and political crisis, which he said presented a new challenge and opportunity.

Blinken said the United States backed Sri Lanka and the International Monetary Fund working out an equitable arrangement on debt restructuring.

"There's an opportunity in this moment, to create a more inclusive, representative, democratic, responsive government," Blinken said. "And to use this crisis to seize that opportunity to make something very positive about a very difficult situation."

He told Cambodian Prime Minister Hun Sen the United States wanted "a strong, positive relationship" between the two countries, in a rare meeting at a time of strained ties over the long-serving leader's crackdown on the opposition and closer military ties with ally China.

The United States has called for greater transparency from Cambodia's over development of its Ream naval base with China's help, which the U.S. sees as Beijing's attempts to build influence in the region.

Blinken announced the United States would provide $25 million to Cambodia in food aid and agricultural cooperation critical to address food insecurity caused by what he called Russia's "aggression" in Ukraine.

(Writing by Kanupriya Kapoor; Editing by Martin Petty)