Trump canceled a visit to Denmark because of its refusal to sell off the sovereign Arctic nation, which experts believe he wants for its vast supplies of natural resources.
The move drew substantial criticism from U.S. and Danish figures, but Pompeo reassured Copenhagen Wednesday it remains a valuable ally and contributor to U.S. security.
"The secretary expressed appreciation for Denmark's cooperation as one of the United States' allies and Denmark's contribution to address shared global security priorities," State Department spokeswoman Morgan Ortagus said. "[The diplomats] also discussed strengthening cooperation with the Kingdom of Denmark -- including Greenland -- in the Arctic."
Danish Foreign Minister Jeppe Kofod said he appreciated the "frank, friendly and constructive talk" with Pompeo and affirmed a "strong bond" between the nations.
"U.S & Denmark are close friends and allies with long history of active engagement across the globe," he tweeted. "Agreed to stay in touch on full range of issues of mutual interest."
It's not yet clear when Trump's visit to Denmark will be rescheduled. Danish Prime Minister Mette Frederiksen has not yet met with Trump since she took office in June.
The U.S. president continued complaining about Denmark in a subsequent post Wednesday, saying it's not meeting a defense spending threshold for a NATO nation -- a complaint he's used against several governments since he took office two years ago.
"For the record, Denmark is only at 1.35% of GDP for NATO spending. They are a wealthy country and should be at 2%. We protect Europe and yet, only 8 of the 28 NATO countries are at the 2% mark. The United States is at a much, much higher level than that. Because of me, these countries have agreed to pay ONE HUNDRED BILLION DOLLARS more - but still way short of what they should pay for the incredible military protection provided. Sorry!"