(CNN) A deadline to end the violence looms over Syria, with another ceasefire due to take effect at sundown on Monday. The US and Russia brokered a pact to pause the violence on Friday after months of back and forth. "That should put an end to the barrel bombs, an end to the indiscriminate bombing of civilian neighborhoods," Kerry saidThe ceasefire will also allow for much-needed humanitarian access to besieged cities like Aleppo. But have raised concerns about how the ceasefire will be monitored and what the consequences of any violations will be. JUST WATCHED Kerry: Key for Syria agreement will be enforcement Replay More Videos ... MUST WATCH Kerry: Key for Syria agreement will be enforcement 08:57He also warned that the truce's success depends on Russia actually putting pressure on al-Assad.

Source: CNN September 12, 2016 12:56 UTC