Baltic countries and Poland have urged the EU to establish a defense line along the border with the Russian Federation, Reuters reported on Thursday, citing a letter from the four heads of state to European Commission President Ursula von der Leyen.

In the letter, the authors highlighted hybrid threats from Russia and Belarus, including disinformation, cyber-attacks, economic pressure, and organized efforts to send migrants from third countries to the EU.Some European diplomats have estimated the cost of building such a defense line along the 700-kilometer border with Russia and Belarus to be around 2.5 billion euros.

This call for a land defense line on the EU's eastern border follows an initiative by Greece and Poland, which envisioned creating an air defense system similar to Israel's Iron Dome. According to Reuters, this initiative would involve coordinating the separate air defense systems of EU countries.