In response to questions on the Russian-Turkish agreement for a ceasefire in Idlib, the Spokesman had the following to say:

The Secretary-General takes note that Russia and Turkey have reached an agreement at the highest level for a ceasefire to go into effect in the Idlib de-escalation area as of midnight.
 
The Secretary-General hopes that this agreement will lead to an immediate and lasting cessation of hostilities that ensures the protection of civilians in northwest Syria, who have already endured enormous suffering.
 
The Secretary-General calls for a return to the UN-facilitated political process mandated by resolution 2254 (2015).
 
Stephane Dujarric, Spokesman for the Secretary-General