Prime Minister Ulf Kristersson said the Scandinavian country's military had analysed which alternatives were available internationally that could meet Swedish demands.

"Based on that analysis, the government has now decided that Sweden will purchase four new frigates in a very large international defence-industrial deal," Kristersson told a press conference, adding that France's Naval Group had been selected to supply the frigates.

"This is one of the largest Swedish defence investments since the Gripen fighter jet was introduced in the 1980s," Kristersson said.

The Nordic country had also evaluated offers from the UK's Babcock together with Sweden's own Saab and Spain's Navantia.

France had said it could deliver a "fully equipped" frigate as early as 2030.

Naval Group was chosen in particular for its ability to make a "quick delivery", Defence Minister Pal Jonson said, adding that it was also a "proven system" with air defence capabilities.

"It is a tripling of Sweden's air defence capability compared with today," Kristersson stressed.

The government said it expected that deliveries of the vessels would begin in 2030.

It did not give an estimated cost for the deal and said the "final price" would be dependent on what armaments and equipment would be included.

When asked for a ball-park figure, Jonson said the average price was expected at "just over 10 billion kronor ($1.1 billion) each".

The deal represents a success for the French group, which suffered a setback last year when neighbouring Norway opted for British-built frigates instead.