U.S. President Donald Trump's threats to take over Greenland have neighbouring Iceland rethinking its long-term defense, currently provided by the United States and NATO as the volcanic island has no military of its own.

Around 74% of Icelanders think Trump's interest in Greenland, and in the Arctic in general, pose a threat to their country, according to a recent poll by public broadcaster RUV.

"We can easily put ourselves in Greenlanders' shoes," said Dagur Eggertsson, an Icelandic member of Parliament for the governing Social Democrats.