France's defence ministry has deployed a nuclear submarine to aid the hunt for the Airbus A330 which disappeared over the South Atlantic on 1 June.
The submarine, S604 Emeraude, is fitted with an array of radar and sonar equipment and will be brought into the search over the next week, says the French defence ministry.
Two French naval vessels are also set to arrive in the next few days.
French support for the search effort for the Air France A330 already includes a Boeing E-3, two Breguet Atlantique 2 aircraft, and a Dassault Falcon 50 maritime patrol jet.