Danish PM Frederiksen speaks on the Workers' International Day at Arbejdermuseet in Copenhagen
Denmark's Prime Minister and head of the Social Democrats Mette Frederiksen speaks on the Workers' International Day at Arbejdermuseet (The Workers Museum) in Copenhagen, Denmark, May 1, 2023. Ritzau Scanpix/Emil Nicolai Helms via Reuters

Denmark's Prime Minister Mette Frederiksen will meet U.S. President Joe Biden in Washington on Monday, amid speculation that the White House will use the visit to vet her as the first female NATO secretary-general.

According to diplomats, Frederiksen, 45, has emerged as a serious contender to replace Jens Stoltenberg, who is scheduled to step down as chief of the North Atlantic Treaty Organization in September.

She stepped into the limelight on the international stage last year as a staunch supporter of Ukraine in its war with Russia, gaining respect for her efforts to strengthen Western unity in the face of conflict.

"I could spend a long time saying good things about Mette Frederiksen. She is one of Europe's most skilled heads of state," Norway's Prime Minister Jonas Gahr Store said last week, when asked about Frederiksen as a potential candidate for the NATO position.

"There is great respect in Europe for the work she has done as prime minister and for the person she is in international cooperation," he said.

The main obstacle for her potential candidacy is that Denmark has long been a laggard in defence spending and has come under pressure to bring military spending up to 2% of GDP, a key goal for NATO member states.

But in December, Frederiksen and her new centrist government moved a plan to meet NATO's target forward by three years to 2030.

Last week, it also announced heavy investments in defence over the next 10 years and increased military aid to Ukraine, which the government said would help to temporarily achieve the NATO target this year and next.

Frederiksen, a career politician who is also head of the Social Democratic Party, became the youngest-ever Danish prime minister in 2019. She won reelection last year after being widely applauded for steering the Nordic country through the COVID-19 pandemic, albeit with a limited profile beyond national borders.

"You may say she didn't really have an international profile," said Jacob Kaarsbo, a security and defence analyst at Think Tank EUROPA. "But that changed when Russia's invasion of Ukraine started."

She has visited Ukraine three times since the war broke out in February 2022. And Denmark has given significant financial and military aid to Ukraine despite major shortcomings in its own defence. The country has also taken a lead in training Ukrainian pilots and said it is open to delivering F-16 fighter jets.

When the Nord Stream pipelines blew up in Danish waters in September last year, Frederiksen responded by forming a rare coalition across the traditional left-right divide, arguing that political unity was needed at a time of international uncertainty.

In February, she pushed through an unpopular decision to scrap a public holiday, which she said was necessary to fund increased defence spending.

"She has a strong position in Denmark, but she is also someone who divides the population. Many see her as too dominant and hungry for power," former Danish defence and justice minister Hans Engell told Reuters.

When former U.S. President Donald Trump in 2019 proposed buying Greenland, a sovereign territory of the Kingdom of Denmark, Frederiksen dismissed the offer as "absurd".

On the international stage, she has managed to stay clear of open clashes with Turkey's President Tayyip Erdogan and Hungary's Prime Minister Viktor Orban, showing her ability to be pragmatic despite conflicting ideologies.

"She's a tough lady and very ambitious. I think she will say yes if she senses that the NATO countries can rally around her, of course especially if Biden asks her," Engell said.

Although she says she is not a candidate, she has stopped short of saying she is not interested in the job: "I'm not applying for any job postings. I have been invited to visit President Biden, which I'm looking forward to."

Finland's President Sauli Niinisto and Ukraine's President Volodymyr Zelenskiy attend a press conference with the Prime Ministers of Sweden, Denmark, Norway and Iceland, in Helsinki
Ukraine's President Volodymyr Zelenskiy and Denmark's Prime Minister Mette Frederiksen attend a press conference at the Presidential Palace in Helsinki, Finland May 3, 2023. Reuters