“There is no alternative,” he told Spanish newspaper El Mundo. “We [Europeans] cannot be the mediators, that is clear … And it cannot be the US either. Who else? It has to be China, I trust in that.”

The stance has caused some consternation among officials and envoys, who are worried about whether publicly courting China is a bad look, when Beijing has shown little outward inclination to help.

Some European capitals are alarmed by China’s refusal to condemn the war, which has ground into its fourth week, or even to describe Moscow’s aggression as “an invasion”.

In Berlin, people close to the governing coalition described an air of “disappointment” regarding Beijing.

Among the Social Democratic Party of Chancellor Olaf Scholz, which maintains close contact with Chinese counterparts, there had been some hope in the early days of the invasion that Xi would use his hotline to Moscow to take on a sustained mediating role.

Now the pervading view is that “the ship has sailed”.

There is a belief that Beijing fudged the opportunity because of a combination of domestic distractions and shock over the scale of the invasion and the united Western front. Those close to the coalition said there was no longer mainstream expectation of a constructive intervention.

Another Western European diplomat said that although outreach was important, Borrell was “tactically wrong”, since China was “neither neutral, nor is the timing right”.

“Only perhaps if China is afraid we would definitively turn away from Beijing may it sink in that it has to make a choice,” they said, adding that the crisis would lead to heightened suspicion of Beijing and other autocratic regimes.

“The only way they can avoid this is if they now come in on the right side and somehow pretend to have been part of the good guys. It’s a lot harder now for Western politicians to ignore Beijing’s actions.”

In Ukraine, hopes that China would positively intervene have faded, two weeks after their respective foreign ministers spoke.

“Any mentions of China as a mediator in the Ukrainian media have passed,” said Maria Shagina, an expert in international sanctions in post-Soviet Europe at the Finnish Institute of International Affairs.

“There was a little blip at the start of March, but even that has faded. It appeared and disappeared – there was nothing meaningful.”

Who’s a war criminal, and who gets to decide?

But Borrell seems undeterred. People close to the Spaniard said he genuinely believed Beijing could play a crucial role in stopping the Russian onslaught, even if his broader views of authoritarian China had become less enthusiastic.

Borrell is briefed regularly on reports in Chinese state media and statements from officials that echo Kremlin disinformation and propaganda.

Reports that Moscow had asked Beijing for military support were seen by Borrell as Russian efforts to draw China into a conflict it had no desire to join, EU sources said.

None of the propaganda has shaken Borrell’s belief that China does not want war in Europe, since it will disrupt the globalised economy on which the industrial juggernaut relies, and that it can be persuaded to act in its own interests to help stop it.

This viewpoint is hotly disputed by geopolitical observers.

“Every time something happens, people say China is in the background, making Russia do something or influencing Russia to move a certain way,” said Temur Umarov, a fellow at the Carnegie Moscow Centre who studies Russian-China relations.

“But I think that’s an oversimplification of the situation here. I don’t believe China has some kind of influence over Putin. Basically, no one has.”

Borrell’s courting of China came on the heels of his strongest public criticisim of Xi, at the Munich Security Forum just four days before the invasion.

“The Russia-China joint statement of February 4 is the culmination of a long-standing campaign,” Borrell said, in reference to a 5,000-word communique agreed by Xi and Putin on the fringes of the Beijing Winter Olympics. “It is an act of defiance. It is a clear revisionist manifesto. A manifesto to review the world order.”

The speech was edited personally by the foreign affairs chief, and aligned closely with his own views on Beijing, sources said.

01:26

Faces of the exodus: fear and anguish as more than 3 million Ukrainians flee Russian invasion

Faces of the exodus: fear and anguish as more than 3 million Ukrainians flee Russian invasion

However, the Russian invasion sparked a tactical rethink. Borrell asked his “good friend” Wang Yi, China’s Foreign Minister, for assurances that Beijing would not take Russia’s side over United Nations resolutions condemning its aggression.

Beijing’s abstentions on two votes were seen as a major victory by EU bureaucrats, who had lobbied intensely at the UN. One described it as “the first major blow for Putin”, and a sign that China would not offer Russia its full backing.

But as European diplomatic efforts escalated, with Borrell and other EU officials then calling on China to help negotiate a ceasefire, there was cynicism in Washington.

The US has constantly demanded that Beijing condemn Russia. On Wednesday, US Secretary of State Antony Blinken described China as being “already on the wrong side of history when it comes to Ukraine”.

EU sources said that the two positions were not necessarily opposed, but were different approaches to achieving the same goal: getting China to help stop the war.

One source, speaking on background, said that Brussels would never go as far as the US. “We’re not America – we want to maintain some kind of relationship with China,” they said.

Brussels is conscious that loudly condemning Beijing would probably scupper any chances of cooperation – a point highlighted by China’s envoy to the US, Qin Gang, in a Washington Post article published on Tuesday.

“Wielding the baton of sanctions at Chinese companies while seeking China’s support and cooperation simply won’t work,” he wrote.

Nonetheless, Borrell and Blinken coordinate regularly, speaking multiple times each week, while their respective deputies, Stefano Sannino and Wendy Sherman, are also in regular contact.

US President Joe Biden will visit Brussels next week, attending the European Council and Nato summits in an effort to further solidify transatlantic cooperation.

02:56

Russian journalist protests against Ukraine war on live TV - and is detained

Russian journalist protests against Ukraine war on live TV - and is detained

A week later, on April 1, a virtual EU-China summit is planned. Official confirmation is expected on Friday, after months of wrangling over dates and agendas. The dynamic makes it an intriguing prospect.

Relations had already stuttered in the 12 months since bilateral sanctions were exchanged last March, while China has yet to name a new EU ambassador, three months after Zhang Ming left the role to become secretary general of the Shanghai Cooperation Organisation.

Although the summit usually focuses on economic issues, with some token discussion of human rights, it will be dominated by Russia’s invasion, and China’s perceived support for Putin.

China’s alleged coercion of Lithuania will be another thorny topic, even if staple talking points such as the stalled EU-China investment deal, China’s human rights record in Xinjiang and Hong Kong, and territorial issues pertaining to Taiwan may take a back seat.

Nonetheless, the EU continues to look for ways to boost its ties with Taiwan.

The bloc’s Political Security Committee, a powerful group of ambassadors sanctioned by China last March, was last week briefed by senior officials on ways to enhance its relationship with Taiwan within the bounds of the one-China policy, the South China Morning Post understands.

In an interview in his office at the European Parliament, former Lithuanian prime minister and current European lawmaker Andrius Kubilius was dubious about the prospect of the EU securing China’s support, but said it was worth a shot.

“For Putin, China is a very important political and economic partner, because he has nobody else with whom to engage,” he said, adding that the summit should not be “dialogue for dialogue’s sake”, and urging focus on Ukraine.

“But it is not realistic to ask China to be a mediator. I would ask the opposite: basically to not intervene; do not take sides with Russia.”