It comes amid an international row over the president’s handling of Denmark’s opposition to the deal, during which he has lashed out wildly at the Scandinavian nation despite previously saying it was “not number one on the burner”.
The US president risked major diplomatic fallout this week when he cancelled his planned state visit over Copenhagen’s refusal to countenance the sale, calling prime minister Mette Frederiksen “nasty” and snubbing Queen Margrethe II.
Officials scrambled to smooth things over, with Mike Pompeo, the secretary of state, praising the Nato member’s status as a US ally in a phone call with his Danish counterpart. Ms Frederiksen has declined to engage in a war of words with the president and insisted their countries remained staunch allies.
Mr Trump made the Puerto Rico quip last year, according to a New York Times report citing a former administration official who overheard it.
Behind closed doors, the president had been discussing the possible purchase of Greenland for more than a year and asked staff to look into the idea, the Times reported.
Puerto Rico is a US territory and Mr Trump has frequently feuded with its political leaders, going so far as to imply in a tweet that it was not part of the US, claiming its officials “only take from USA”.
He was criticised for the perceived slow pace of the US government’s response to devastation wrought there by Hurricane Maria in 2017, a storm that killed thousands and wrecked infrastructure.
And he has repeatedly and falsely claimed that Washington supplied $91bn (£74bn) in federal aid to Puerto Rico for reconstruction, when in fact this figure reflected official estimates of how much it could receive in the next two decades.
As recently as April this year Mr Trump called Carmen Yulin Cruz, the mayor of San Juan and his most prominent critic on the island, “crazed and incompetent”.
On Thursday Ms Cruz described Mr Trump’s tenure in the White House as an “absurd presidency”, in response to a news story about the Denmark saga.
Also on Thursday, Denmark’s former prime minister attacked Mr Trump for tweeting that Copenhagen was not contributing enough to Nato. Countries that did not spend 2 per cent of their GDP on defence were “way short of what they should pay for the incredible military protection provided” to them by the US, the president claimed on Wednesday.
Lars Løkke Rasmussen, who led Denmark until June, tweeted: “We have had (proportionally) exactly the same numbers of casualties in Afghanistan as US. We always stands firm and ready. We will not accept that our defence willingness is only about percentages.”
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