Frederiksen has spent recent months rallying European leaders against President Donald Trump's renewed interest in annexing the Arctic island, an effort that opinion polls suggest has bolstered her popularity after public dissatisfaction over rising living costs and pressures on welfare services.
"This will be a decisive election, because it will be in the next four years that we as Danes and as Europeans will really have to stand on our own feet. We need to define our relationship with the United States, and we must rearm to ensure peace on our continent," Frederiksen said.
"We must stick together in Europe, and we must secure the future of the Danish Commonwealth," she said, referring to the Danish Kingdom which consists of Denmark, Greenland and the Faroe Islands.
The Greenland crisis has further raised Frederiksen's profile on the international stage, where she gained attention for her swift response in navigating Denmark through the COVID-19 pandemic and for building European support for Ukraine.
The election will test whether voters reward her international leadership and defence of Danish sovereignty or punish her government for what critics say has been an inattention to problems at home.
Denmark's current government is an unusual cross-partisan coalition of Frederiksen's Social Democrats, the centre-right Liberal Party led by Defence Minister Troels Lund Poulsen, and the Moderates, led by Lars Lokke Rasmussen, the foreign minister who has twice served as prime minister.
Created in 2022 as a crisis government, the coalition stands to lose its majority, according to opinion polls, as parties reposition themselves along more traditional left-right lines.
The Social Democrats suffered a significant defeat in the 2025 municipal elections, losing the Copenhagen mayoralty for the first time in 87 years.
While the party's support plummeted to 17 per cent in December polls, it has since rebounded to 22 per cent as Frederiksen's approval ratings got a lift from her handling of the Greenland dispute. In the 2022 general election, the party won 28 per cent of the vote.
The government's 2023 decision to abolish the Great Prayer Day public holiday to fund higher defence spending was unpopular, despite broad public support for military investment.
Some economists say scrapping the holiday was unnecessary, given the country's recent strong economic growth. The Green Left party, a traditional ally of the Social Democrats that is currently in opposition, has pledged to reinstate the holiday if elected, a proposal the Social Democrats have not ruled out.
