WARSAW, Poland (AP) — Patriot missile batteries that Poland acquired from the U.S. last year have been deployed to the country’s capital Warsaw as part of military exercise, according to Poland’s defense ministry.

Poland is taking additional steps to strengthen its defensive capabilities as Russia’s war in neighboring Ukraine enters its second year later this month.

At least three ground-to-air missile launchers were seen Monday at Warsaw’s Bemowo airport.

Defense Minister Mariusz Blaszczak said on Twitter over the weekend that the redeployment of the missile batteries from their base in Sochaczew, central Poland, to Warsaw was “an important element to the training” of the 3rd Warsaw Brigade of Missile Air Defense.

The Patriot batteries are part of Poland’s multibillion dollar armaments purchases from the U.S., South Korea and elsewhere.

Poland has also received Patriot batteries from Germany, to boost its air defenses in the east, where a stray missile came from across the border with Ukraine and killed two civilians last year.