SINGAPORE—U.S. Defense Secretary Lloyd Austin called on his Chinese counterpart to avoid destabilizing actions over Taiwan and said in their first face-to-face meeting that U.S. policy toward the island hadn’t changed.

After a nearly one hour closed-door meeting on the sidelines of a defense conference in Singapore, both sides gave accounts that suggested an easing of tensions after President Biden said recently that the U.S. would intervene militarily to defend Taiwan if Beijing moved to seize the island.

China reacted angrily to Mr. Biden’s comments, which were quickly rolled back by the White House. Mr. Biden later said there was no change to U.S. policy. Mr. Austin told Chinese Defense Minister Gen. Wei Fenghe in their Friday meeting that the U.S. stance of recognizing but not endorsing China’s claim to Taiwan was unchanged, according to the U.S. account.

The meeting was the first in-person exchange between top-level U.S. and Chinese officials since Mr. Biden made his comment about U.S. military intervention to support Taiwan during a visit to Asia in May.

Chinese defense ministry spokesman Wu Qian said Gen. Wei told Mr. Austin that Taiwan is an inalienable part of China and its status quo can’t be changed. Both sides emphasized the need to keep open lines of communication to head off crises.

“The meeting wasn’t long, but the effect was positive,” Mr. Wu said. “It is better to meet than not to meet, it is better to talk than not to talk.” A U.S. defense official said the meeting went twice as long as scheduled.

Gen. Wei Fenghe of China and Secretary of Defense Lloyd Austin are each set to address a Singapore conference this weekend, after a bilateral meeting Friday.

Photo: Xinhua/Zuma Press; Michael Reynolds/EPA/Shutterstock

The two men also discussed Russia’s invasion of Ukraine, and North Korea, according to a U.S. account of the meeting.

Gen. Wei told Mr. Austin that Beijing would continue to try to promote peace talks between Russia and Ukraine, according to Mr. Wu.

Senior State Department officials told reporters ahead of the meeting that the U.S. has continued to express concerns to Beijing about what they called its tacit support for Russia’s invasion of Ukraine, but declined to say whether Mr. Austin planned to press the issue with his Chinese counterpart.

The men spoke ahead of the opening of the Shangri-La Dialogue, an annual defense conference organized by the London-based think tank International Institute for Strategic Studies. Mr. Austin is set to make a speech at the conference in Singapore on Saturday morning local time, followed by Gen. Wei on Sunday morning.

Japanese Prime Minister Fumio Kishida opened the conference with a speech on Friday warning that China was seeking to change the status quo in the Asia-Pacific region with increased military activity, such as jet-fighter and bomber flights near Japan and Taiwan.

Mr. Kishida said a rapid buildup of nuclear threats from North Korea and China meant Japan had to increase military spending, and instability in the region could tip into crisis.

“I have strong concerns that East Asia could soon face the same situation as Ukraine,” Mr. Kishida said.

The conflict in Ukraine has shifted the world’s attention away from the Asia-Pacific, a region that many defense analysts say harbors the risk of a major clash as China builds up its military and claims a greater sphere of control. Increased Chinese military flights near Taiwan and joint air and naval exercises between China and Russia near Japan in recent weeks have raised concerns among the U.S. and its allies.

China has likewise complained about U.S. naval operations in disputed stretches of the South China Sea, calling them a provocation that infringes on Chinese sovereignty.

Frequent North Korean missile tests this year and warnings from the U.S. and South Korea that Pyongyang is preparing for its seventh nuclear test have added to instability in the region.

Write to Alastair Gale at alastair.gale@wsj.com and Keith Zhai at keith.zhai@wsj.com