European officials were stunned that President Trump restated his desire for Greenland after a yearlong effort to dissuade him, according to diplomats and others.

Allies including France and Germany are working closely on a plan on how to respond should the United States act on its threat to take over Greenland.

Trump administration officials are set to meet with Danish officials about Greenland on Wednesday, diplomatic sources tell CBS News.

Trump allies have cited the island's continued role in missile defense infrastructure, accusing Denmark of leaving it vulnerable to potential Russian and Chinese influence.

Countries in Europe reportedly are working on a plan if the Trump administration makes a move on acquiring Greenland, which is a a Danish territory.

The White House has kept all options for acquiring Greenland on the table, refusing to rule out military action.

Europe, led by the UK and Germany is exploring a stronger NATO presence in Greenland to reinforce Arctic security following US President Donald Trump’s call for American ownership and reported invasion planning.

U.S. Secretary of State Marco Rubio on Wednesday said that he would meet with Denmark next week, as U.S. President Donald Trump has repeated in recent days that he wants to gain control of Greenland.