Spain will send warships and could send fighter jets to Bulgaria and France stands ready to send troops to Bulgaria.

The Netherlands will send two F-35 fighter aircraft to Bulgaria from April and is putting a ship and land-based units on standby for NATO's Response Forces.

As ERR News previously reported, Denmark is sending a frigate with a crew of 160 and more F-16 fighter jets to Lithuania.

Secretary-General Jens Stoltenberg said in a statement on Monday NATO will "take all necessary measures to protect and defend all allies".

He said: "We will always respond to any deterioration of our security environment, including through strengthening our collective defense."

The U.S.A and U.K. are also mulling sending more troops to the Baltics.

Prime Minister Kaja Kallas (Reform) called on the U.S.A to send more forces in an interview with the Financial Times published on Monday.

Russia has been massing forces and military equipment on Ukraine's eastern border for several months leading some analysts to believe a further invasion is imminent.

Russia has demanded NATO remove its forces from the eastern flank, resetting the border to its 1997 limit. Last week it announced military drills with Belarus.

A week of negotiations between Russia, the U.S. and NATO ended with no clear result.

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