Toyota is recalling 670,000 of its 2004-9 Prius hybrids in the United States to fix problems involving the loss of steering and the hybrid powertrain shutting down, the automaker has told the National Highway Traffic Safety Administration.

The move is part of a worldwide recall of almost 2.78 million vehicles, according to The Associated Press, which quoted Toyota officials in Japan. Only the Prius is affected in the United States. Outside the United States the recall covers the Corolla and the Wish, a small van.

The cars are being recalled because the metal used for a steering component is not hard enough, according to a report the automaker filed on Wednesday with the safety agency. The part could wear out “if the steering wheel is frequently and forcefully turned to the full left or full right position while driving at low speeds,” and that “could result in the loss of steering ability,” according to the report.