Newsom, who is being touted as the leading Democrat to challenge the Republicans in the next US presidential election, is urging Europe to roar back against Trump.
"It's time to get tough. Time to get serious and stop standing on the sidelines. It's time to show some backbone," he said, according to Sky News upon arrival at the World Economic Forum in Davos.
The governor believes that the European leaders' handling of Trump is pathetic and embarrassing.
"I can't stand this complicity; people are just lying down. I should have brought a bunch of knee pads for all the world leaders here."
Newsom advises Europe to stand united.
"Trump is a T. rex. You mate with him or he devours you. It's one or the other, and you have to resist."
