The collision between the and the Japanese vessel occurred Monday evening south of the Strait of Hormuz, which lies between Iran and Oman.
Pentagon spokesman Todd Vician says neither ship was seriously damaged.
"No injuries were reported nor was there any damage that affected the navigation or the seaworthiness of either vessel," he said.
A spokesman for the Japanese shipping company said the tanker will check the extent of the damage at a port in the United Arab Emirates.
The Japanese vessel was traveling from the Persian Gulf to Singapore, with eight Japanese and 16 Filipino sailors on board.
The has a crew of 127.
The cause of the collision is being investigated.
In February 2001, a U.S. submarine accidentally sank a Japanese fishing and high school training vessel off the coast of Hawaii. Nine people were killed. The delay by the submarine captain in apologizing for the incident triggered protests by the victims' families.