NATO chief Jens Stoltenberg will take over as Norway's central bank governor at the end of the year, officials said Friday, a controversial choice that has already raised concerns about the bank's independence.

The appointment comes amid escalating tensions between the West and Russia. Western nations fear Moscow has plans to invade Ukraine, which aspires to join the NATO alliance.

But Stoltenberg, a 62-year-old trained economist, insisted Friday he would stay on as NATO secretary general until the end of his term in October.

"Until my mandate at NATO ends on October 1, I will devote all my strength and attention to leading the Alliance", he told a press conference in Norway via video link.

"It's absolutely necessary at a time when Europe and North America must stand together", he added.

The central bank and finance ministry said he would take over "around December 1".

Norway's central bank determines monetary policy but also manages the country's enormous sovereign wealth fund, the biggest in the world.

Worth 11.76 trillion kroner (more than 1.17 trillion euros, $1.33 trillion), the fund controls around 1.4 percent of the world's market capital.

A former prime minister and finance minister in his native Norway, Stoltenberg applied for the job after the finance ministry contacted him, and he thanked the government for the vote of confidence.

"I was intent on finding the best central bank governor for Norway, and I'm convinced it's Jens Stoltenberg", Finance Minister Trygve Slagsvold Vedum said in a statement.

"The combination of financial training, an understanding of society, and management experience that few Norwegians have, make him very qualified as head of the central bank", he said.

Stoltenberg beat out the central bank's deputy governor Ida Wolden Bache for the job. She was hoping to become the bank's first woman governor since its creation in 1816.

She will now serve as interim governor until Stoltenberg takes over, as the current head Oystein Olsen is to retire this month at the age of 70.

NATO Secretary General Jens Stoltenberg, who has been selected to taken over Norway's central bank, is a trained economist who previously served as his country's finance and prime minister
NATO Secretary General Jens Stoltenberg, who has been selected to taken over Norway's central bank, is a trained economist who previously served as his country's finance and prime minister AFP / JOHN THYS

The selection process has made headlines in Norway, where commentators and politicians have raised concerns about potential political nepotism due to Stoltenberg's longstanding ties to the ruling Labour Party.

Stoltenberg headed the Labour Party from 2002 until 2014, when he took over as NATO chief, and he is still a party member.

The current Labour party leader and prime minister is none other than Stoltenberg's protege Jonas Gahr Store, who recused himself from the appointment process in order to avoid any conflict of interest.

Most political parties in parliament, including those close to the government, had expressed their opposition to Stoltenberg's appointment in advance, arguing that it could harm the bank's independence, or at the very least, its image.

"It's not the smartest appointment, as demonstrated by the turmoil surrounding his candidacy and the questions about the central bank's independence", Kari Elisabeth Kaski, a spokeswoman on economic affairs for the Socialist Left Party which occasionally cooperates with the government, told news agency NTB.

Several officials have also said they plan to grill the government over media reports of shadowy backdoor meetings.

A poll published in January by television station TV2 indicated that 66.6 percent of those surveyed wanted Wolden Bache to be appointed, while only 25.7 percent supported Stoltenberg, even though he is a very popular figure in Norway.

Aged 49 and with a PhD in economics, Wolden Bache has held several senior positions at the central bank but has also worked at Handelsbanken Capital Markets.

The finance ministry also asked her to apply for the job.

Some 43 percent meanwhile said they did not have faith in the selection process.

The central bank governor's mandate is for six years.