President Joe Biden said Tuesday that the United States was not seeking to distance itself from China but in fact wanted an improved relationship, as he prepared for a highly anticipated summit with President Xi Jinping in San Francisco.

The two leaders will meet on the sidelines of the APEC summit in California for their first encounter in a year as trade tensions, sanctions and the question of Taiwan have fueled quarrels between the world's largest economies.

"We're not trying to decouple from China. What we're trying to do is change the relationship for the better," Biden told reporters at the White House shortly before heading to San Francisco.

Asked what he hoped to achieve at the meeting, he said he wanted "to get back on a normal course of corresponding; being able to pick up the phone and talk to one another if there's a crisis; being able to make sure our military still have contact with one another."

But Biden also warned that the United States was wary of investing in China due to Beijing's business practices.

"I'm not going to continue to sustain the support for positions where if we want to invest in China, we have to turn over all our trade secrets," he said.

Positive momentum from November 2022 talks between Xi and Biden in Bali was derailed when the United States shot down an alleged Chinese spy balloon, delaying a planned visit to Beijing by US Secretary of State Antony Blinken.

Since then, a flurry of high-level diplomacy, including Blinken's eventual trip to China in June, has signaled a willingness on both sides to mend ties.

Asked about Beijing's expectations for the summit, China's foreign ministry remained vague, mentioning "in-depth communication" and "major issues concerning world peace."

China has also made clear that it will not budge on issues it considers red lines, such as Taiwan, which Beijing claims as its own territory awaiting reunification, and its military expansion in the South China Sea.

But Washington and Beijing have recently made some progress on trade and economic relations, and climate change talks.

"If in fact the Chinese people, who are in trouble right now economically, if the average homeowner, if the average citizen in China, was able to have a decent paying job — that benefits them, and benefits all of us," Biden said Tuesday.

Xi will have dinner with top US business leaders on his trip, and is expected to push for a relaxation of US trade curbs in his talks with Biden.