Brussels, 3 April 2023 (dpa/MIA) - Finland is to become the 31st member of NATO on Tuesday, the alliance's Secretary General Jens Stoltenberg has announced.

"We will raise the Finnish flag for the first time here at NATO headquarters," he said on Monday in a press conference ahead of a meeting of the alliance's foreign ministers in Brussels.

Finland applied together with Sweden for NATO membership in May 2022 in the aftermath of the Russian invasion of Ukraine, but its application got tangled up in Ankara's opposition to Sweden's entry.

All NATO members must unanimously agree to admit new members. After months of talks brokered by the alliance, Turkey eventually relented and voted to admit Finland into NATO last week.

The decision ends Finland's decades-long neutral status amid perceived security risks due to Russia's full-scale invasion of Ukraine.

The Nordic country shares a 1,340-kilometre-long border with Russia.

Finland is to be formally welcomed to the alliance with a flag-raising ceremony to mark the country's accession to NATO, Stoltenberg said.

Sweden's membership is still pending Turkish ratification due to a number of sticking points, among them Ankara's concerns over what it says is a lack of cooperation in fighting terrorism.

Among other things, Turkey continues to block Swedish accession on the grounds that Sweden refuses to extradite 120 people viewed by Ankara as terrorists.