Former UK Prime Minister Boris Johnson, who is in Washington for negotiations with high-ranking politicians on increasing support for Ukraine, has called for Ukrainian troops to be provided with all the weapons they need.

Johnson supported providing Ukraine with all the types of weapons it needs, in response to a question about F-16 fighter jets. 

"All I will say is that every time we have said it will be a mistake to give such and such an item of weaponry, we end up doing it, and it ends up being the right thing for Ukraine," Fox News quotes Johnson.

"I remember being told that it was the wrong idea to give them the anti-tank shoulder-launched missiles. Actually, they were indispensable, and the United States under Donald Trump gave them the Javelins as well. They were indispensable in those battles to repel the Russian tanks," the former British Prime Minister said.

"People said that we should not give the HIMARS [to Ukraine]. I remember having arguments about the multiple-launch rocket systems, the MLRS. Actually, they have proved invaluable for the Ukrainians. And the same with tanks," Johnson added. 

Johnson believes it is necessary to "save time, save money, save lives, and give the Ukrainians what they need as fast as possible". 

Johnson rejected the idea that Russian President Vladimir Putin might be ready to turn the war into a nuclear conflict.

"He [Putin] probably does not even stop the Ukrainians if he did that, and we would put his economy into such a cryogenic paralysis that Russia would not come out of it for decades. So he is not going to do that," Johnson said.

Johnson will meet with US Republican lawmakers during the week to urge them to continue aid to Ukraine.