Polish Prime Minister Donald Tusk during a visit to the border with Belarus in Ozierany Wielkie, 11 May 2024. Photo: EPA-EFE/PAWEL SUPERNAK

The leaders of Poland, Latvia, Estonia and Lithuania have called for the construction of a defence line along the EU’s external borders with Russia and Belarus, Reuters reported on Wednesday, quoting a letter from the four to Ursula von der Leyen, the president of the European Commission.

The four countries’ leaders argued that the line was needed to protect the EU from military and hybrid threats, the latter referring to a combination of cyber-attacks, economic pressure and the funnelling of migrants from third countries across the borders in an attempt to destabilise all four.

“The scale and costs of this joint endeavour require a dedicated EU action to support it both politically and financially,” the letter said.

Preliminary estimates put the cost of building such a defence line along the 700-kilometre EU border with Russia and Belarus at around €2.5 billion, Reuters said. The project is due to be discussed at a two-day summit of EU leaders in Brussels starting on Thursday.

Reacting to the content of the letter, Russian Foreign Ministry spokesperson Maria Zakharova simply responded by saying, “As long as the spikes are facing inwards.”

Ministers from all four countries warned last year that they had been “facing unprecedented pressure caused by illegal migration” since mid-2021, adding that the route via Belarus was being exploited by Russia to continue destabilising Poland, the Baltic States and the rest of the EU.