The revelation comes after the Swedish government blocked the construction of 13 offshore wind farms in the Baltic on November 4, and stopped another off the island of Gotland on November 21 due to the military's defence concerns.

On Wednesday the military said all wind farm projects in the Baltic would pose a problem.

"The Swedish Armed Forces have been clear in their evaluation regarding offshore wind energy in the Baltic Sea," the military said in an email to AFP.

"It would pose unacceptable risks for the defence of our country and our allies," it added.

The government said the towers and rotating blades of wind turbines emit radar echoes and generate other forms of interference.

The relative proximity of the 13 blocked projects to the "highly militarised" Russian exclave of Kaliningrad, which is sandwiched between Poland and Lithuania, had been "central" in the government's assessment, Defence Minister Pal Jonson said.

He said wind farms in the area could delay the detection of incoming cruise missiles, cutting the warning time in half to 60 seconds.

"We currently see no technical solutions or legal prerequisites for a coexistence of our defence interests and wind power in the Baltic Sea," the Armed Forces said on Wednesday.

"The greatly deteriorated security situation after Russia's full-scale invasion of Ukraine means that we can no longer accept any risks to our defence capability."

"Our ability to detect incoming threats against both Sweden and our allies is vital. Our sensor chain plays a decisive role in this and it must be able to operate with the highest possible capability," it said.

Tensions have mounted in the Baltic since Russia's 2022 invasion of Ukraine.

With Sweden and Finland now NATO members, all of the countries bordering the Baltic are now members of the alliance except Russia.

The Swedish government has insisted that wind power expansion remained a priority, with electricity consumption expected to double by 2045 from the current level.

It has said other areas off Sweden's southwestern and northeastern coasts were better suited for offshore wind projects.