The International Syria Support Group (ISSG), a body of diplomats including the US, Russia, the UN, and several other nations, has met in Vienna today and issued a statement threatening to expel violators of the Syrian ceasefire from the deal.
The statement warns that if all the co-chairs agree that a party is in a “pattern of non-compliance” they can refer the matter to the other ISSG members for a discussion to potentially exclude that party from the ceasefire in the future.
The statement suggests this would be an extremely slow process, and with both the US and Russia in the group, the prospect that the two would agree on the same violator seems really unlikely. At any rate, the Syrian ceasefire is fairly shaky at this point at any rate, with fighting having resumed in several regions, and everyone accusing everyone else of violating it.
This appears to have been the primary statement out of the Vienna talks, which also points to international attempts at getting peace talks going again not being particularly successful, something EU officials have complained is the result of the US and Russia cutting everybody out of the important talks, and then being unable to make any bilateral deals at any rate.