The U.S. military announced its blockade has turned away another 20 vessels, U.S. Central Command said Sunday. File Photo by EPA

Aug. 10 (UPI) -- The U.S. military said it blocked an additional 20 ships from reaching or leaving Iran's ports, as prospects for a resumption of negotiations on ending the war look bleak.

U.S. Central Command announced in a statement Sunday that its blockade has redirected 55 commercial vessels, up from 35 on Aug. 2. It has also disabled two vessels and boarded two others.

The U.S. military resumed its blockade of Iran's ports on July 14 amid a resumption in fighting between Washington and Tehran over control of the Strait of Hormuz.

The United States is seeking to regain freedom of navigation of the vital energy trade route that Iran has claimed control of since the war between the two erupted in late February.