A team of international chemical weapon disarmament experts has arrived in Syria to begin their work on removing the country’s chemical weapon stockpile.

The mission was set up after a joint U.S.-Russia deal supported by the UN.

The experts with the Organization for the Prohibition of Chemical Weapons are tasked to destroy chemical weapons during an active war for the first time. Syria’s foreign minister said that seven of the 19 sites that contain chemical weapons are in active combat areas.

The BBC is reporting that truces between the government and local militia will likely be necessary to reach the seven locations.

The country is believed to possess more than 1,000 tons of chemical weapons. While not confirmed, Syria is believed to also have the extremely deadly VX nerve agent.