"What we see from Russia is an illegal and illegitimate effort to destabilize a sovereign state and create a contrived crisis with paid operatives across an international boundary," Kerry told the Senate Foreign Relations Committee.
Ukrainian officials said security forces drove pro-Russian protesters out of the regional government headquarters in Kharkiv and arrested about 70 of them, but demonstrators continue occupying the Donetsk regional administration in the nearby region. The protests come a month after Russia annexed the Crimea peninsula, a move the West has not recognized.
President Barack Obama and Congress have imposed sanctions on Russia in response to the annexation, and Kerry signaled the additional penalties on Russian energy, banking and mining could be imposed if Moscow fails to honor a sovereign Ukraine. Kerry said the US and European allies were united and willing to impose tough new sanctions.
Kerry said he would meet next week in Europe with Russia Foreign Minister Sergey Lavrov and Ukrainian officials. He said Russia has a choice and can work with the international community.
A defiant Kerry engaged in testy exchanges with several of the Republicans on a committee he once led, defending the Obama administration's policies on Syria, the Middle East, Russia and Iran.
"On major issues, this administration is failing badly," Sen John McCain, a leading Republican, told Kerry.
Kerry defended US involvement in negotiations with Syria, Israel and the Palestinians and Iran.
"You declare them all dead. I don't," he told McCain. "We'll see what the verdict is.
