The rebel group has been engaged in intense fighting with government forces in the region, leading to the displacement of thousands of people and hundreds of deaths.
Youseff emphasised the importance of the ceasefire in addressing the humanitarian crisis in the region.
"Obviously it's a welcome decision for an organisation that strives to be close to victims, to those who need help. So let's hopefully make the best use of it. I hope everyone agrees with it, abides by the cessation of hostilities across the frontline so that we can really use that momentum to increase our humanitarian support, to bring in much medical aid, food, water, and equipment, and so on, so that the response can be truly dignifying to those I think left with no hope anymore," Youseff said.
--SABC/ChannelAfrica--