U.S. officials are rushing to come up with options for business deals and other ways to step up links to Greenland, taken by surprise by President Donald Trump’s renewed demand to take over the island, people familiar with the matter said.

Trump has long wanted the territory for what he says are security reasons. But after a flurry of activity on the issue early last year, including a trip there by his vice president, once-urgent efforts to realize the president’s vision moved to the back burner, according to the people, who asked not to be identified speaking about matters that aren’t public.

But his sudden flurry of public comments about taking Greenland in the days following the U.S. operation to capture former Venezuelan strongman Nicolas Maduro on Jan. 3 has made the issue a top priority again. On Tuesday, the White House said it wouldn’t rule out military action, while European leaders issued an unprecedented warning to dissuade Washington from trying to seize territory from a NATO ally.