U.S. President Obama does not believe that 'safe zones' are a practical alternative in Syria right now, the White House said Monday.

Syria's Bashar Assad needs to live up to its commitments to a cessation of hostilities, the White House added.

"The Assad regime needs to live up to the commitments that they've made, and we would like to see the Russians use the influence that they have with the Assad regime to get them to do it," White House spokesman Josh Earnest told reporters.