According to Cameron, there is a debate in the United States about how actively and for how long assistance should be provided to Kyiv.

"I know that the argument that European security is American security, that dictators should not be appeased, will prevail. But I want to assure them that we will stay the course and mobilize other allies too," he said in an op-ed published by The Sun on Sunday.

Earlier, Cameron called on NATO arms firms to supply Ukraine for at least two years.