Poland’s Prime Minister Donald Tusk said a treaty he is set to sign with President Emmanuel Macron on Friday will open the way toward potentially sharing the protection from French nuclear missiles.

The pact due to be 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 in Warsaw. 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 US military support for Ukraine and growing pressure from U.S. President Donald Trump on European allies to take responsibility for their own defense.

Tusk said earlier this year that Poland is in “serious talks” with France over Macron’s proposal to use his country’s nuclear capabilities to defend European allies. The prime minister also warned the continent could face war with Russia in the next few years.

“The treaty of course opens up the possibility which we will describe later in technical and financial details,” Tusk said on Friday.

Successive Polish governments have staked the country’s security on forging close relations with Washington. Warsaw has spent billions of dollars on contracts with U.S. defense contractors and picked US-based Westinghouse Electric Co. reactors for its first atomic energy plant.

Poland also succeeded to convince the U.S. to station about 10,000 troops on its soil, a long-sought security goal. But the attempts to lobby the previous U.S. administration to get Warsaw involved in its nuclear-sharing program yielded no results.

“Strengthened military cooperation with European powers is something that is expected by our American ally,” Tusk told reporters. The treaty doesn’t present an alternative to transatlantic relations, but will complement them, the prime minister said, adding that Poland is working on a similar security pact with the U.K.

Rearmament

The nuclear push adds to Warsaw’s already ambitious rearmament program spurred by Russia’s full-scale invasion of its neighbor Ukraine more than three years ago. Poland has been ramping up military investment by purchasing weapons from the U.S. and South Korea, in part to replace military equipment donated to Kyiv.

Warsaw plans to spend a record $46 billion for defense this year, or 4.7% of economic output, up from around 4% last year.

But the embrace of Macron’s proposal could face a number of obstacles. France’s nuclear shield is independent of the NATO security guarantees which extend to Poland. Warsaw is also committed not to acquire atomic weapons itself as a signatory to the nuclear Non-Proliferation Treaty.

Tusk said that the agreement is set to forge closer ties between Warsaw and Paris as Poland and France seek a stronger voice in the European Union. The new German Chancellor Friedrich Merz visited Warsaw on Wednesday, the same day he also met Macron for his first foreign trip.

The latest diplomatic push comes little more than a week before Poles vote in a crucial presidential election on May 18 with national security emerging as one of the key topics in the campaign.

“This gives an idea of ​​not only how Poland’s position is growing, but also how much of a safer country we are becoming,” said Tusk.

With assistance from Agnieszka Barteczko.