HELSINKI (AP) — Estonia and Latvia plan jointly to acquire German air defense systems for the protection of the two NATO nations' airspace in what would be the biggest defense cooperation deal between the Baltic neighbors that border Russia, the Estonian and Latvian defense ministries said Sunday.

According to the provisional deal, deliveries of the medium-range IRIS-T SLM air defense system — manufactured by weapons maker Diehl Defence of Germany — could begin in 2025.

The value of the deal and detailed information about the numbers of the system weren’t disclosed as talks with the supplier are still ongoing, defense ministries of the two countries said.

Estonian Defense Minister Hanno Pevkur described the deal as “a joint project of historical proportions for our defense cooperation, the largest one to date” between Tallinn and Riga.

“Presuming that negotiations are successful, we (Estonia and Latvia) hope to reach contract and, subsequently, announce the official winning bidder this summer,” Pevkur said in a statement.

The German air defense system, consisting of truck-mounted launchers, missiles and a separate command vehicle, is designed to protect cities, armies and civilian population from air attacks, and being effective at neutralizing planes and helicopters.

The system can be used for protection from a host of other threats, such as unmanned aerial vehicles, cruise missiles and loitering munitions.

“Our jointly selected medium-range air defense system will further secure the skies of Latvia and Estonia and will provide the maximum possible protection for our people, as well as civil and military infrastructure,“ Latvian Defense Minister Inara Murniece said in a statement.

Germany has delivered IRIS-T air defense systems to Ukraine where, according to media reports, they have been successfully used against Russian targets since late last year during Moscow's war on Kyiv.