WASHINGTON — The Obama administration is accusing Russia of firing artillery to hit Ukrainian military sites and planning to send pro-Russian separatists more lethal weaponry.

The State Department says the U.S. has evidence that Russia is shelling Ukraine from sites inside Russia. Spokeswoman Marie Harf also says the U.S. has evidence Russia intends to deliver “heavier and more powerful multiple rocket launchers” to separatists battling Ukrainian forces in the east of the country.

Harf declined to provide details or elaborate on the evidence because she said she could not get into intelligence “sources and methods.”

The U.S. has repeatedly accused Russia of stoking the Ukraine rebellion and alleges that Russia is ultimately responsible for last week’s downing of a Malaysian airliner over eastern Ukraine.