NUUK, Greenland — Denmark's prime minister has told the U.S. during a visit to Greenland that “you cannot annex another country,” even with the argument that international security is at stake. U.S. Secretary of State Marco Rubio, meanwhile, said on Friday that Copenhagen “should focus on the fact that the Greenlanders don’t want to be a part of Denmark.” Danish Prime Minister Mette Frederiksen was wrapping up a three-day visit to the strategically critical Arctic island on Friday as U.S.