The Prime Minister met with other world leaders at a summit in Bavaria, amid speculation about the appetite of Western leaders to continue to support Ukraine during a prolonged conflict, as consequences such as spiralling energy prices are felt across the globe.
Mr Johnson said Vladimir Putin must not be allowed to “hack” Russia’s neighbour apart with impunity.
French President Emmanuel Macron and German Chancellor Olaf Scholz are among those also at the meeting in Bavaria, and ahead of a meeting with Mr Macron yesterday, Mr Johnson was asked whether France and Germany are doing enough over Ukraine and said: “Just look at what the Germans alone have done.
“I never believed in my lifetime that I would see a German Chancellor stepping up in the way that Olaf Scholz has and sending weaponry to help the Ukrainians to protect themselves.
“He’s made huge, huge strides.
“We have four per cent of our gas from Russia, in Germany it’s 40 per cent.
“They’re facing real, real pressures, they’re having to source energy from elsewhere. But they’re doing it. They’re making the effort. They’re making the sacrifice.”
He said the Germans realise “the price of freedom is worth paying”, despite the domestic consequences.
Mr Johnson added: “The consequences of what’s happening for the world are tough.
“But the price of backing down, the price of allowing Putin to succeed, to hack off huge parts of Ukraine, to continue with his programme of conquest, that price will be far, far higher and everybody here understands that.”
It comes as Mr Johnson said he would be “honoured” to host Ukrainian President Volodymyr Zelensky for a state visit in the UK.
It was reported in yesterday’s Sunday Times that Ministers were considering offering Mr Zelensky a state visit, including a meeting with the Queen.
“I think that Volodymyr Zelensky has done an absolutely amazing job of leading his country and leading world opinion in an appalling time,” Mr Johnson told ITV News.
Asked if he wanted to offer the Ukrainian leader a visit, he added: “If he ever becomes free to leave and it makes sense for him to leave Ukraine, then obviously the UK would be only too honoured to host him.
“But the most important thing is for us to continue to be united here at the G7. And we are.”
Mr Zelensky will address G7 leaders by video link today.