President-elect Donald Trump has tossed expansionist rhetoric at U.S. allies and potential adversaries with arguments that the frontiers of American power need to be extended into Canada and the Danish territory of Greenland,

European leaders this week expressed confusion and pushed back against President-elect Donald Trump's refusal to rule out using military force to take over Greenland.

MILAN - Several European leaders have cautioned Donald Trump against violating the sovereignty of other NATO allies across the continent, following comments by the U.S. president-elect that did not rule out using military force to annex Greenland's territory.

European leaders reacted to Trump's statement at a press conference on Tuesday that he would not rule out military action to take control of Greenland. He had earlier vowed to slap high tariffs on Denmark if it refused to cede its autonomous territory.