URGENT – Syria ceasefire sunset

US Secretary of State John Kerry (Photo: SAUL LOEB/AFP/Getty Images)

US Secretary of State John Kerry (Photo: SAUL LOEB/AFP/Getty Images)

(CNN) — The sun has set in western Syria on Monday. According to the terms of a deal brokered by the United States and Russia, sundown marked the start of a temporary ceasefire. US Secretary of State John Kerry said the deal would stop the Syrian air force from attacking opposition targets. The ceasefire will also allow for much-needed humanitarian access to besieged cities such as Aleppo.