MUNICH — The West should not rule out the military option in Ukraine, NATO's top military commander said on Saturday, adding that he was referring to the possibility of helping Ukraine with weapons and equipment rather than sending in soldiers.

"I don't think we should preclude out of hand the possibility of the military option," U.S. Air Force General Philip Breedlove told a group of reporters at the Munich Security Conference, when asked whether he backed supplying defensive weapons to the Ukrainian army in its battle against pro-Russian separatists.

He said he was referring to providing weapons or capabilities, not sending soldiers. "There is no conversation about boots on the ground," he said.

Breedlove said proposals put forward by Russian President Vladimir Putin to end the conflict in eastern Ukraine were "completely unacceptable."