California Governor Gavin Newsom urged European leaders meeting at the Davos forum to take a tough stance against U.S. President Donald Trump, particularly over his remarks regarding Greenland.

Newsom described Trump as “weak,” calling on the European Union to abandon appeasement and apply direct pressure.

He said Trump’s ambition to acquire the Danish island was “irrational,” but ruled out a U.S. military option, arguing that firm political confrontation would be sufficient to deter him.