US National Security Advisor Jake Sullivan and top Chinese diplomat Wang Yi met in Vienna this week, Washington and Beijing announced Thursday, as the two powers seek to maintain communication amid soaring tensions, especially over Taiwan.

The two held eight hours of talks stretching over Wednesday and Thursday in the Austrian capital, ending an unofficial pause in high-level contacts since the United States shot down a Chinese surveillance balloon that had traveled across the country in January and February.

Both sides described the previously unannounced meeting as "candid, substantive and constructive," covering topics including the Russian invasion of Ukraine and Taiwan, according to the White House -- two of the most sensitive subjects in the frosty relationship between the world's top two economies.

Washington has repeatedly warned China against offering any military assistance to Russia, and is closely watching its moves over Taiwan -- which Beijing claims as its own territory.

The self-ruled island lives under the constant fear of a Chinese invasion, and Beijing has stepped up its rhetoric and military activity around it in recent years.

Wang "comprehensively expounded upon China's solemn position" on Taiwan, Chinese state-run news agency Xinhua said, adding the two diplomats "agreed to continue to make good use of this strategic channel for communication."

- Getting past balloon incident -

The balloon incident, which China labelled an accident but which Washington viewed as an act of espionage, caused Secretary of State Antony Blinken to cancel a long-planned trip to meet his counterpart in Beijing.

Just after the incident, Blinken met with Wang on the sidelines of the Munich Security Conference, during which he warned China not to repeat such an "irresponsible act."

Wang in turn said that their countries' relations had been damaged by how Washington reacted.

But the apparent diplomatic thaw in Vienna is likely to reignite speculation about a rescheduling of Blinken's trip or potential meeting between US President Joe Biden and Chinese leader Xi Jinping.

The pair last spoke on the sidelines of the G20 summit in Indonesia in November 2022.

Asked about the issue Wednesday, Biden said there had been progress.

- US seeks cooperation on drugs -

In a background briefing for reporters, a senior US administration official stressed that just having the Sullivan-Wang meeting was a step forward.

The idea was to "try to find a few issues where there are some overlapping interests," the official said.

"We've made no secret that we see maintaining channels of communication as particularly important in times of tension, that it's important to manage competition," the official said, adding that both sides agreed on that.

Sullivan and Wang discussed Indo-Pacific regional security issues, and the top Biden aide pressed Wang for better cooperation in fighting drug trafficking, the official said.

Washington says Chinese firms supply the chemicals that Mexican drug cartels use to make fentanyl, responsible for a massive spike in drug overdose deaths in the United States.

"We raised our concern about the lack of communication on this issue and pressed for constructive engagement," the official said.

On Taiwan, the official said the United States stressed that the two sides had managed the issue "for over 40 years without conflict" and that Washington did not want to see any unilateral change to the "status quo" in the situation.

- It takes two -

Chinese diplomats have kept up a steady drumbeat of criticism against America, and Xi made a rare direct rebuke of Washington in March, accusing "Western countries led by the United States" of trying to undermine his country.

Biden has said he will not do China any favors in the competition between the two superpowers, but has vowed he would do everything possible to keep the rivalry from descending into conflict.

Sullivan, in a major speech on 27 April outlined the US strategy to build a "fairer, more durable global economic order" -- and singled China out for mention.

"We're looking to manage competition responsibly and seeking to work together with China where we can," he said.

AFP