Chinese President Xi Jinping on Friday told top US diplomat Antony Blinken that the world's two biggest economies should be "partners, not rivals", but that there were a "number of issues" to be resolved in their relations.

Blinken, in China for the second time in less than a year, met leading Chinese politicians in the capital Beijing, where US officials said he would directly raise crucial areas of difference including Russia, Taiwan and trade.

Meeting Blinken in Beijing's Great Hall of the People, Xi said the two countries had "made some positive progress" since he met with US President Joe Biden last year, according to state broadcaster CCTV.

"The two countries should be partners, not rivals," Xi said.

"There are still a number of issues that need to be resolved, and there is still room for further efforts," the Chinese leader added.

"We hope the US can also take a positive view of China's development," he added.

"When this fundamental problem is solved... relations can truly stabilise, get better, and move forward."

Earlier China's foreign minister Wang Yi warned Blinken that US pressure could trigger a "downward spiral", as the visiting diplomat raised concerns on issues including support for Russia.

Wang also warned that the question of self-ruled Taiwan was the "first red line" that must not be crossed in China-US relations.

Blinken described his talks with Wang at the Diaoyutai state guesthouse -- which lasted more than five and a half hours -- "extensive and constructive".

The top US diplomat will speak to journalists later on Friday at the American embassy in Beijing.

'Negative factors'

China has been infuriated by Biden's pressure on the economic front -- which is unlikely to ease during an election year -- including a sweeping ban on semiconductor exports and efforts to wrest blockbuster video app TikTok away from its Chinese owners.

Wang told Blinken that relations between the two countries were "beginning to stabilise", especially after Biden and Xi met in November near San Francisco.

"But at the same time, the negative factors in the relationship are still increasing and building," Wang said.

"China's legitimate development rights have been unreasonably suppressed and our core interests are facing challenges," he said, urging "respect for each other's core interests"

"Should China and the United States keep in the right direction of moving forward with stability, or return to a downward spiral?

"This is a major question before our two countries and tests our sincerity and ability."

Hopes for progress

US officials and experts believe that Xi's foremost priority is to manage headwinds in the Chinese economy and that, at least in the short term, he is looking to avoid flare-ups with the West.

Blinken raised concern with Wang about China's support for Russia, which has rapidly rebuilt its military base two years into its invasion of Ukraine, State Department spokesman Matthew Miller said.

Russian President Vladimir Putin said this week he will visit China in May.

As he opened the meeting with Wang, Blinken said China and the US should manage the relationship "responsibly" and added: "I hope we make some progress on the issues our presidents agreed" on at the California summit.

The two countries should be as "clear as possible about the areas where we have differences -- at the very least to avoid misunderstandings, to avoid miscalculations", Blinken said.

"That really is a shared responsibility that we have not only for our own people, but for people around the world, given the impact that our relationship has," he said.

Biden, who recently spoke by telephone with Xi, faces a tough re-election fight in November against his predecessor Donald Trump, who has cast China as an enemy and vowed a hard line.

The Biden administration has highlighted wins achieved by its diplomacy with China including what officials say is the first crackdown in years by Beijing on producers of precursor chemicals to fentanyl, the painkiller behind an addiction epidemic in the United States.

But while open to cooperation, Biden has increased pressure on China beyond Trump in some areas.

In the latest move, the US Congress, with Biden's support, voted to force the divestment of TikTok from Chinese company ByteDance or risk a ban in the United States.

US officials allege security and privacy concerns over the app, which has taken off among US teenagers.

ByteDance denies the allegations and has insisted it has no intention of selling.