The official -- who spoke on condition of anonymity -- said Undersecretary of Defense for Policy Elbridge Colby would attend in Hegseth's place, but did not provide a reason for the Pentagon chief's planned absence from the February 12 meeting.

President Donald Trump recently plunged NATO into its deepest crisis in years by threatening to take Greenland by force, insisting that Washington must control alliance member Denmark's autonomous Arctic territory for security reasons.

The unpredictable US leader ultimately backed off after saying he had struck a "framework" deal with NATO chief Mark Rutte to ensure greater American influence, but his demands still rocked the alliance.

In a gesture of solidarity, a modest number of military personnel were deployed to Greenland in January by a handful of European countries including France, whose President Emmanuel Macron described the standoff as "a strategic wake-up call for all of Europe."

Top EU diplomat Kaja Kallas has meanwhile urged Europe to step up efforts on defense and play a bigger role in NATO, saying Trump has "shaken the transatlantic relationship to its foundation."