Kerry told reporters Tuesday if Syria doesn’t begin the process of removing Assad by Aug. 1, there will be serious consequences, The Associated Press reports.

“If Assad does not adhere to this, there will clearly be repercussions,” Kerry said. “One of them may be the total destruction of the cease-fire and then go back to war. I don’t think Russia wants that. I don’t think Assad is going to benefit from that. There may be even other repercussions being discussed. That is for the future.”

Kerry emphasized opposition rebels will never put up with Assad staying in power.

“If Assad’s strategy is to somehow think he’s going to just carve out Aleppo and carve out a section of the country, I got news for you and for him: This war doesn’t end,” Kerry said. “As long as Assad is there, the opposition is not going to stop fighting.”