"You can see that supply and demand ... is in balance today and this should bring down the stock levels of the world," Dudley told reporters on the sidelines of the St Petersburg International Economic Forum.

"It looks to me like an agreement that everyone is working hard to comply with and it's helpful to rebalance oil markets. It's somewhat unprecedented for countries to cooperate like this, and I think it's healthy for oil markets."

(Reporting by Olesya Astakhova and Christian Lowe; Editing by Katya Golubkova)