As he appealed for continued for Ukraine, the secretary-general of the alliance said Ukraine’s territorial gains could not have been possible without the support of Nato.
Despite the recent gains, Mr Stoltenberg told Politico that a Russian victory would be “bad for all of us in Europe and North America, in the whole of Nato, because that will send a message to authoritarian leaders — not only Putin but also China — that by the use of brutal military force they can achieve their goals.”
Joe Biden’s administration has described China as America’s greatest threat within its national security strategy.
The Nato chief said: “It is important for Nato allies to stand together and to address the consequences of the rise of China — and that we agree on, and that’s exactly what we are doing.”
While describing China as a long-term geopolitical threat, Mr Biden has continued to call on US lawmakers to provide support Ukraine against Russia.
Both the US and UK have heavily supported Ukraine throughout the war with the former providing over $17billion (£14.7billion) in security aid.
The UK has provided £2.3billion in military assistance to Ukraine since the war began and has pledged to match that figure next year.
The UK is also hosting a training programme with the aim of training 10,000 new and existing Ukrainian personnel within 120 days.
Despite the support from the US and UK, Mr Stoltenberg warned European allies must do more and should match the spending requirement of the alliance.
“I strongly believe that European allies should do more,” he said. “The reality is that 80 per cent of Nato’s defence expenditure comes from non-EU allies.”
In 2014, Nato members agreed to spend at least two per cent of GDP on defence by 2025. So far, just 10 of the 30-member alliance do so – the UK spends 2.29 per cent.
Although Rishi Sunak has insisted he will continue the UK’s support for Ukraine during a call with Volodymyr Zelensky this week, it is unclear if he will match a pledge by his predecessor, Liz Truss, to boost defence spending from two per cent to three per cent by 2030.