Iceland's government has lodged a formal protest with the United States after US President Donald Trump shared a social media map appearing to fold the country into US territory.

According to a ministry statement, Iceland's Foreign Minister Thorgerdur Katrin Gunnarsdottir called the US ambassador to deliver a firm objection, telling the envoy the map was simply unacceptable.

The image, posted Monday, showed a redrawn North America with Canada, Greenland, Mexico and Iceland all shaded in stars and stripes and captioned as a single "United States of America" — with no caption or context explaining the intent behind it.

Just days earlier, Icelanders had rejected a government push to resume EU accession talks in a 29 August referendum, a vote held partly in the shadow of Trump's own designs on Greenland.

The incident lands awkwardly given how central the US is to Icelandic security. Iceland has had no armed forces of its own since becoming independent in 1944, and instead relies on its NATO membership as one of its founders and a defence pact with Washington dating to 1951 for protection.