Crude oil prices surged Sunday, as the U.S. and Iran teetered on the brink of a renewed war after attacks on commercial ships in the Strait of Hormuz.

"We have had progress but there is still a big distance between us," Iran's chief negotiator told state media.

Iranian gunboats fired on a tanker trying to pass through the Strait of Hormuz after Tehran announced its closure, and a second vessel was hit by a projectile, according to maritime authorities.