Polish Prime Minister Donald Tusk said a treaty he signed with President Emmanuel Macron on Friday will pave the way toward potentially putting Poland under the protection of France's nuclear-missile shield.

The pact sealed in the eastern French city of Nancy will include a pledge of mutual military assistance in an event of an armed conflict and extend into defense industry cooperation, Tusk told reporters. He described the provisions in the treaty as "groundbreaking from the point of view of our security.”

The move to forge the economic and military cooperation between both countries comes amid uncertainty over the extent of the future U.S. military support for Ukraine and growing pressure from U.S. President Donald Trump on European allies to take responsibility for their own defense.