Putin aide warns U.S. on Ukraine, says Russia could act

KIEV (Reuters) - A senior Kremlin aide accused the United States on Thursday of arming Ukrainian "rebels" and, urging the Kiev government to put down what he called an attempted coup, warned Russia could intervene to maintain the security of its ex-Soviet neighbour.

Sergei Glazyev, an adviser to President Vladimir Putin with responsibility for relations with Ukraine, told a newspaper that U.S. "interference" breached the 1994 treaty under which Washington and Moscow jointly guaranteed Ukraine's security and sovereignty after Kiev gave up its Soviet-era nuclear arsenal.