(Reuters) -The U.S. National Highway Traffic Safety Administration (NHTSA) on Thursday asked owners of some vehicles of Swedish automaker Volvo to urgently complete a safety recall over a brake failure issue.

Volvo issued a recall in June for 11,469 vehicles of a number of models due to a loss of brake function.

The remedy for the Volvo recall is to update vehicle software through an over-the-air download, which as of July 15 has not been done by about 1,000 vehicles, the NHTSA said in a statement.

"Without this recall remedy, an affected vehicle could completely lose its ability to brake while going downhill," it said.