"With the handover to Ukraine, these are Ukrainian weapons," Faber told German newspaper Berliner Morgenpost, specifying that this applies to all material, including Leopard 2 tanks.   "With the Russian attack on Ukraine, the territory of both states is a war zone. The use of the weapons is subject to the provisions of international law."Ukrainian forces crossed the border into Kursk Oblast on Aug. 6, resulting in clashes on Russian soil that were described by Russian President Vladimir Putin as "a large-scale provocation."Kyiv has largely refused to comment on the operation in Kursk Oblast, which takes place just as Russia is ramping up attacks in Ukraine's Donetsk Oblast.Faber also posted on X that Ukraine's incursion "forces Russia to withdraw forces from the east" and is "completely legitimate and makes military sense.