FGM-148 Javelins are man-portable anti-tank missiles that have an effective firing range of 75 to 2,500 meters (up to 8,200 feet).
Previously, the United States repeatedly said that its military aid to Ukraine would be non-lethal only.
During his September 2014 visit to the United States, Ukrainian President Petro Poroshenko requested lethal military assistance from Congress, but Washington has not granted his request.
The Russian Foreign Ministry emphasized the United States would breach agreements on the Ukrainian settlement reached in Geneva on April 17, 2014 by Russia, the EU, the US and Ukraine, if it supplied lethal weapons to Kiev.
The military confrontation between Kiev forces and independence supporters in eastern Ukraine began in April 2014 and recently intensified despite a ceasefire agreement reached in September.