REYKJAVIK — Icelanders voted Saturday on whether to restart European Union membership negotiations shelved in 2013, in a referendum that opinion polls show is too close to call and that Prime Minister Kristrún Frostadóttir moved forward after President Trump's repeated interest in taking control of neighboring Greenland.

The yes-or-no question asks the country's roughly 265,000 eligible voters whether Iceland should resume accession talks with the European Commission. A yes vote would trigger negotiations across 35 policy areas, followed by a second referendum on any final deal, parliamentary approval and a constitutional amendment. More than one in five voters had already cast early ballots before Saturday, according to Iceland's public broadcaster RÚV.

The polling

A Gallup poll conducted this week put the no campaign ahead at 51.6 percent to 48.4 percent, Al Jazeera and the Guardian reported. An earlier survey by Icelandic pollster Maskina had the yes side narrowly in front at 51.3 percent, Al Jazeera reported. Polls close at 22:00 GMT and the first results are expected between 10 p.m. and midnight local time.

The Greenland shadow

Frostadóttir, whose center-left government took office in 2024, brought forward the vote after Trump's statements about U.S. control of Greenland, the self-governing Danish territory 180 miles from Iceland. The country is a founding member of NATO but has no armed forces and relies on a 1951 bilateral defense pact with Washington. Foreign Minister Thorgerdur Katrín Gunnarsdottir told Reuters that Iceland has been "disappointed" with the U.S. "pressure campaign waged against both Greenlanders and Denmark", Al Jazeera reported. Frostadóttir has cast joining the EU as "one of the biggest risk-reducing steps we can take", the BBC reported.

The opposition case

Opponents, led by Guðrún Hafsteinsdóttir of the Independence Party, argue that Iceland already enjoys most of the benefits of European integration through the Schengen zone and the European Economic Area single market, without the sovereignty costs of full membership. She framed the vote as a decision on whether to hand "decision-making powers" to Brussels on fisheries, agriculture and natural resources, the BBC reported. Fishing and marine industries account for nearly 40 percent of Iceland's exports, and the EU's Common Fisheries Policy — which would open Icelandic waters to Spanish, Dutch and other trawlers — is widely seen as the biggest obstacle to any final deal. Farmers fear a similar squeeze on the meat and milk producers who have started to earn higher prices in recent years, the Guardian reported. Former Prime Minister Katrín Jakobsdóttir told the AP that Iceland is "better off outside of the EU, within the close collaboration with the EU", dismissing the case for full membership.

Frostadóttir has pledged that Saturday's outcome is not final. "This is not an election about membership and not about adaptation, as there will be another referendum on an accession agreement if the result is yes," she told a rally, according to the AP. Results are due in the early hours of Sunday.