The White House said Monday that it's "unfortunate" Russia is pursuing a policy in Syria that is not leading to peace, and said the U.S. coalition leading the fight against the Islamic State will never let Russia stop its efforts to find a political solution.

Propping up a "murderous regime" and targeting the country's water supply indicates that Russia failed to truly pursue peace, Josh Earnest said on Monday. He said the question is, "When will they try something new?"

A cease-fire brokered between the U.S. and Russia collapsed last week amid charges from the Obama administration that Russia never stopped bombing moderate Syrian forces. It fell apart almost immediately when a U.N. convoy of humanitarian aid was bombed, and the U.S. blamed Russia.

Over at the State Department, a spokesman said Monday that so far there was no clear plan on how to proceed in Syria, and said the ball is in Russia's court. In the meantime, Earnest said that bombing U.N.-led convoys "only fuels extremism."

He said the U.S. is pursuing peace, and said it's "unfortunate that the Russians are pursuing a strategy that is in such direct conflict with that." He said the best way to judge Russia's intentions is to "see what they do" rather than listening to what they say.

When asked if President Obama was naive to ask Russia to help craft and uphold a cease-fire, Earnest said the White House will never apologize for seeking a peaceful solution to the conflict there.

The U.S. "won't apologize for pursuing peace," Earnest said. The U.S. "didn't have to make any concessions to the pursue peace."