LONDON

The three Baltic states and Poland have asked the European Union to build a defense line along their collective 700-kilometer (435-mile) border with Russia and Belarus, to protect the bloc from military and other threats from Moscow, local media reported Thursday.

The leaders of Latvia, Lithuania, Estonia, and Poland – all EU member states – drafted a letter to the EU president outlining the proposal and its cost and asking for other member states' financial and political support, according to the Kyiv Independent daily.

“The creation of a system of defense infrastructure along the external border of the EU with Russia and Belarus will meet the acute and urgent need to protect the EU from military and hybrid threats,” the newspaper quoted the letter as saying.

The defense line would also meet NATO's military requirements, with EU officials estimating the cost to be around Є2.5 billion ($2.7 billion).

"The scale and costs of this joint endeavor require a dedicated EU action to support it both politically and financially," added the letter, written as Russia's war on neighboring Ukraine is into its third year.

"Extraordinary measures need to be employed as the EU's external border must be protected and defended with military and civilian means," said the leaders.

Earlier this month, Poland reinstated a buffer zone at its eastern border with Belarus after a soldier was fatally stabbed in what officials claimed was an attack by illegal migrants assisted by Belarusian security forces.

In May, Polish Prime Minister Donald Tusk and his Greek counterpart Kyriakos Mitsotakis urged the European Commission to form a Europe-wide air defense shield to supply the bloc's airspace with protection from alleged Moscow aircraft, missiles, and drone threats.