The US and Russian ambassadors clashed over Ukraine in a rare joint appearance in Beijing on Monday.
Nicholas Burns, the United States ambassador, told the World Peace Forum in Beijing that Russia's "unprovoked" invasion was "the greatest threat to the world order".
"Russia's war in Ukraine, the fact that Russia crossed the border with an armed force, unprovoked, and has started this war with so much human suffering, so many innocent civilians dead - this is a direct violation of the UN Charter," the ambassador told the event, which was hosted by Tsinghua University.
Do you have questions about the biggest topics and trends from around the world? Get the answers with SCMP Knowledge, our new platform of curated content with explainers, FAQs, analyses and infographics brought to you by our award-winning team.
He also warned that other countries were suffering because Russia's blockade of Ukraine's ports had disrupted grain exports.
"There's a food security crisis. It's been compounded by this illegal, unjust and brutal war of the Russian Federation against Ukraine," he said.
The two ambassadors shake hands before the event at the World Peace Forum. Photo: AP alt=The two ambassadors shake hands before the event at the World Peace Forum. Photo: AP>
But Andrey Denisov, the Russian ambassador, who spoke after Burns, said he "totally disagreed" with the comments and his American counterpart had ignored the backdrop of Nato expansion.
"Nato, in essence, is involved in the war with Russia through proxies," Denisov said.
He also insisted: "There is no blockade [of grain exports]. All the corridors are open. The latest step by Russia is withdrawing troops from Snake Island."
Snake Island, a critical outpost for controlling Black Sea shipping lanes, was abandoned by Russian forces last week in what Moscow said was a gesture of goodwill. Ukraine said the Russians had been forced to retreat under a heavy barrage of artillery and missile fire.
Denisov praised Beijing for its "reasonable and balanced" approach, adding: "Basically, our colleagues here in China say that they clearly know where the roots of the Ukraine crisis are."
China has so far refused to condemn Russia's invasion and has criticised the imposition of sanctions and Nato's eastward expansion, saying the alliance has created more conflict rather than resolving problems.
Densiov said China had been calling on all sides to take a constructive position, and suggested it may be able to "play a role" as mediator.
"China has a good relationship with Ukraine. And that's where I hope that in one way, China can send some kind of signal to our neighbours to be more realistic," he said.
The British and French ambassadors also spoke at the event, with the UK's Caroline Wilson joining Burns to dismiss claims that Nato, which she described as a "pure defensive alliance", was a threat to Russia.
"Russia has a border of 20,000km [12,000 miles], and it is an extremely big country," she said. "One 16th of that border is with Nato countries, so the prime responsibility of the war is clear, the prime responsibility is with Russia."
Burns had earlier said: "You [Russia] accepted Nato enlargement. You dealt with all these countries, and now you try to say that somehow they don't have a right to their own independence and sovereignty."
Meanwhile, French ambassador Laurent Bili said China and Europe both wanted a peaceful solution and should work together to stop the fighting and increase humanitarian assistance to help "alleviate the consequences of the war".
"For example, China can join in Food and Agriculture Organization activities to get Russia to stop blocking food exports from Ukraine and to solve the problem of the food crisis," he said.
Burns also accused China of spreading "Russian propaganda" and urged the foreign ministry to "stop accusing Nato of starting the war".
He said: "I would hope the Chinese foreign ministry spokesperson would also stop telling lies about American bioweapons labs, which do not exist in Ukraine ... These lies are the behaviour of an authoritarian regime that routinely doesn't tell the truth."
Chinese foreign ministry spokesman Zhao Lijian rejected Burns's criticisms, telling a press briefing on Monday: "It is the US official that has been spreading disinformation."
Jia Qingguo, an international relations professor at Peking University, told the event that although Nato had not threatened Russia, Moscow felt that countries trying to join the bloc were hostile towards it.
"The fact is, you can say that Nato has not threatened Russia," he said. "But the problem is Russia feels that way."
This article originally appeared in the South China Morning Post (SCMP), the most authoritative voice reporting on China and Asia for more than a century. For more SCMP stories, please explore the SCMP app or visit the SCMP's Facebook and Twitter pages. Copyright © 2022 South China Morning Post Publishers Ltd. All rights reserved.
Copyright (c) 2022. South China Morning Post Publishers Ltd. All rights reserved.