An American naval crew has begun destroying Syrian chemical weapons on board a U.S. container ship in the Mediterranean.

The Pentagon says it will take about two months to destroy the 600 metric tons of chemical agents, which include mustard gas and the raw materials for sarin nerve gas.

The ship Cape Ray is equipped with a hydrolysis system that uses substances like water and sodium hydroxide to make chemicals safe enough to be disposed of at commercial sites.

Officials say the ship is in international waters, and that many precautions have been taken to ensure the operation will not pose a serious risk to the environment. They say the processed material will be transferred to Finland and Germany for final disposal.

Syria agreed to hand over its chemical weapons in response to a United Nations agreement brokered last year.

Syrian President Bashar al-Assad came under intense pressure to hand over his country’s stockpile of chemical weapons following the deaths of hundreds of people in a sarin gas attack last year on the outskirts of Damascus.

Western countries accuse Assad’s forces of unleashing the nerve agent. The Syrian government blamed rebels in Syria’s civil war, which is now in its fourth year.

The Organization for the Prohibition of Chemical Weapons said in June that the removal of the chemicals from Syria is unprecedented, because the nation is still in a state of internal armed conflict.

  chemical weapons, destruction, National, navy, syria, u.s.a., world