The United States and Russia have agreed to new steps that they say could make a difference in Syria's civil war. Neither side spelled out what the new steps will be.

But both Moscow and Washington stressed that closer cooperation between their governments was critical to ending the Syrian conflict. As many as half a million people have died since fighting began between President Bashar al-Assad's government, rebel factions, and a number of terrorist groups back in March 2011. The conflict has also contributed to a global migration crisis.