Following NATO’s chief’s suggestion that the military alliance might not object to Poland’s request that German Patriot air defense batteries be delivered to Ukraine, Germany said on Friday that it was discussing the proposal with partners.

Poland’s… idea is being discussed by us and our allies, a German government official told reporters in Berlin.

Following a stray missile that landed and killed two people in Poland last week, Berlin offered Warsaw the Patriot system to assist defend its airspace. Later, German Defense Minister Mariusz Blaszczak requested that Ukraine get the fire units.

NATO Secretary-General Jens Stoltenberg said such deployments should be decisions for individual nations, taking into account rules around final users.

“The specific decisions on specific systems are national decisions,” he told reporters in Brussels.

“Sometimes there are end users’ agreements and other things, so they need to consult with other allies. But at the end of the day, it (the decision) has to be taken by the national governments,” he added.

Stoltenberg’s comments came after German Defense Minister Christine Lambrecht on Thursday said sharing Germany’s Patriot units outside NATO territory would require prior discussions with NATO and the allies.

Patriots are produced by the U.S. company Raytheon.

On Friday, the Polish president said it was Germany’s decision where its Patriot air defence units are stationed, adding that it would be better for Poland’s security if they were on Ukrainian territory near the border.