China will be a chief player in the modification of Iran’s heavy-water reactor, based on the nuclear agreement sealed this week in Vienna.

Chinese Foreign Minister Wang Yi

Chinese Foreign Minister Wang Yi

Chinese Foreign Minister Wang Yi announced on Tuesday July 14, after the marathon negotiations between Iran and the 5+1 reached their culmination, that modifying the Arak heavy-water reactor was one of the core issues in the negotiations and that China and the U.S. will co-chair the joint working group overseeing the modifications.

The Chinese foreign minister told reporters that China’s unique role in the negotiations was to table the idea of the modification, adding that his country would promote the process and enhance communication with Iran.

The IAEA and the West believed that the Arak heavy-water reactor had the potential to be used in building nuclear weapons.

According to the deal reached on Tuesday in Vienna, Iran has agreed to a redesign of the reactor.

The Chinese foreign minister stressed that it will work closely with Iran on this matter.

Iran and the 5+1 finalized a deal to end their 12-year nuclear disputes on Tuesday July 14, agreeing that in exchange for concessions in Iran’s nuclear program, all international sanctions against the country are to be lifted.