DAVOS, Switzerland/COPENHAGEN, Jan 20 - U.S. President Donald Trump on Tuesday vowed there was "no going back" on his goal to control Greenland, refusing to rule out taking the Arctic island by force and rounding on allies as European leaders struggled to respond. 

Trump's ambition - spelled out in social media posts and mock-up AI images - to wrest sovereignty over Greenland from fellow NATO member Denmark has threatened to blow apart the alliance that has underpinned Western security for decades.