French President Nicolas Sarkozy said Friday that he did not believe in the sincerity of Syrian leader Bashar al-Assad, nor in the UN-backed ceasefire aimed at halting 13 months of bloodshed. \"I do not believe in Bashar al-Assad\'s sincerity, nor unfortunately in the ceasefire. I think we must deploy observers so that at the very least we know what is happening,\" he said in an interview with French television I-Tele.