Russia has not fulfilled its promise to end support for members of illegal armed groups operating in eastern Ukraine, U.S. Secretary of State John Kerry has said after a meeting of the foreign ministers of NATO member states.

"Russia has not lived up to its promises to end all support for armed separatists, withdraw troops and weapons, release hostages, allow OSCE inspectors to do their jobs, and respect Ukraine's sovereignty and territory," he said at a press conference in Brussels on Tuesday.

Kerry said that since the September 5 Minsk ceasefire agreement, Russia had "funneled several hundred pieces of military equipment and material – including tanks, armored personnel carriers, and heavy artillery pieces – directly to pro-Russian separatists in Ukraine."