We don't want to see that happen," said spokesman Mark Toner said. "We think that that would have damaging consequences to the cessation."
Sanctioning the two groups that are parties to a cessation of hostilities agreement in Syria, would be an obstacle as the U.S. tries to "de-escalate the situation on the ground”, Toner said. "We don't believe that that's constructive.”
The truce in Syria agreed to by the U.S. and Russia -- co-chairs of International Syria Support Group working to find a solution to the crisis in the country -- excluded Daesh and al-Nusra.
Russia's Permanent Representative to the U.N., Vitaly Churkin, recently proposed the U.N. place sanctions on Ahrar Al-Sham and Jaysh al-Islam, claiming the groups were linked to al-Qaeda and Daesh.
The request had been previously proposed by Russia, Toner said