Syrian dictator Bashar Assad must turn over his chemical weapons in order to avoid military reprisal by the United States, but President Obama’s spokesman can’t say if the regime will retain biological weapons.

“I’ll have to defer that to the experts who are negotiating this, perhaps the State Department or others — the team that’s going with Secretary Kerry,” White House press secretary Jay Carney said during the Wednesday briefing. “What is obviously directly of concern here was the use of chemical weapons by the Assad regime. But I think that’s a question that’s worth following up on.”