The United States and China agreed on Friday to reestablish "healthy economic relations", US Treasury Secretary Janet Yellen said.

She spoke after two days of meetings with Chinese Vice Premier He Lifeng in San Francisco.

"We do not seek to decouple our economy from China's," Yellen said after the meeting. "This would be damaging to both the US and China and destabilizing to the world."

The talks helped lay the groundwork for a meeting next week between President Joe Biden and Chinese President Xi Jinping on the sidelines of the Asia-Pacific Economic Cooperation summit in San Francisco.

Thawing of relations

Yellen also said she accepted an invitation from He to travel to China next year.

"Over the past two days, Vice Premier He and I have built on this foundation, with frank, direct and productive discussions," she said.

A trade war, launched by former US President Donald Trump, concerns over increasing Chinese aggressiveness in Asia and the Pacific — especially regarding the autonomy of Taiwan — and China's support for Russia amid its invasion of Ukraine have all soured relations between the two superpowers.

But a series of talks between high-ranking ministers over the past months has seen the relationship between the world’s largest economies improve.

"Our mutual desire, both China and the United States, is to create a level playing field and ongoing, meaningful and mutually beneficial economic relations," Yellen said. "That is our main focus."

The question of Russia

While Yellen and He have agreed to improve communication, the US will not shy away from taking unilateral action against Chinese firms supplying defense equipment to Russia, if Beijing fails to take action, she told reporters.

"I stressed in our conversations... we would like to see China crack down," she said, without accusing the Chinese state of direct involvement.

"We are concerned that in spite of a sanctions programs that we've put in place, that equipment that is critical to Russia's military effort is nevertheless evading sanctions and being delivered to Russia," Yellen said.