WARSAW, Poland (AP) — Poland's frayed efforts to buy Patriot missiles from U.S. arms producer Raytheon, a deal valued at around $7.6 billion, could be concluded by the end of the year, the country's defense minister said Friday.

Antoni Macierewicz, said at a news conference in Warsaw that the government and the U.S. company "concluded a very important stage of our discussions on the acquisition of medium-range missile systems to ensure Poland's security."

Though conceding that the talks have been difficult and "not always in an atmosphere of understanding and full of friendship," Macierewicz said the deal could be signed around the end of the year if certain conditions are met.

For one, he said an earlier price tag by Raytheon of 50 billion zlotys ($12.7 billion) was "unacceptable" and that Poland has made it clear it will pay no more than 30 billion zlotys ($7.6 billion).

The plan to buy the Patriot missiles is part of a broader army modernization plan meant to improve Poland's security in light of Russia's resurgence.

Macierewicz also said talks must still be held on off-set deals. They include a demand that Polish industry take part in the production of Raytheon's low-cost interceptors, the SkyCeptor.

Deputy Defense Minister Bartosz Kownacki said the missile system would help protect against Russian missiles in Kaliningrad, a Russian region on Poland's northeastern border.

Both Raytheon and the U.S. Embassy in Warsaw expressed satisfaction that the deal is moving forward.

Raytheon said the air defense system has been used in combat by five nations and that since 2015 it has intercepted more than 100 tactical ballistic missiles during combat operations.