KYIV, May 29 – Ukraine will use U.S.-made Javelin anti-tank missile systems in case pro-Russian forces in Donbas mount an offense, President Petro Poroshenko said.

"Javelin is, first and foremost, a defensive weapon. The Ukrainian Armed Forces will use them exclusively in case of provocations or an offensive of Kremlin-controlled militants," Poroshenko wrote on Twitter on Monday, May 28.