Rex Tillerson said the United States should have employed a military response to Crimea to keep Russia from acting more aggressively in Ukraine.

“Clearly the sanctions that were put in place in response to Crimea did not deter them from entering Ukraine,” Tillerson said, adding that the U.S. response to Crimea “was less than the leadership of Russia thought they would encounter.”

“Sanctions were going to [be] insufficient to deter Russian leadership from taking the next step,” Tillerson added, suggesting that “there should have been a show of force, a military response, in defensive posture…to send a message that it stops here.”

But when challenged to clarify whether he would have committed U.S. troops to fight against Russian troops in Ukraine, Tillerson appeared to backpedal a bit, saying that a military response would not be “a first option.”

He explained he would have wanted a “Ukrainian military force supported by the U.S. providing them with capable, defensive weapons” to conduct the operation.