The rout of Russian troops in north-eastern Ukraine has raised hopes among Nato allies that a well-supplied army could liberate even more territory, strengthening demands to rapidly expand the supply of western arms to Kyiv.

The unprecedented and widely unexpected Ukrainian advance has emboldened officials from the US, UK and more hawkish EU countries, multiple officials told the Financial Times citing private conversations over the weekend, given the counter-offensive was under way as western defence ministers met in Germany to discuss maintaining weapons supplies.

“The tone has shifted, without a doubt,” said a senior European diplomat. “You won’t really hear anyone talking against more weapons now, just a chorus of supporters and one or two staying silent.”