Iran has discovered a new oilfield with 53 billion barrels of crude oil, Rouhani has said, a discovery that might improve the country's proven 150 billion barrel reserves by a third.

The new oilfield in the southwestern province of Khuzestan holds an estimated 53 billion barrels of crude, Mr. Rouhani said, while speaking live on state television from the central city of Yazd

The discovery would add about 34 per cent to Iran's current proven oil reserves.

ILKHA