Brazil's president believes it will be technically possible to find the wreckage of the Air France jet that crashed in the Atlantic earlier this week, and salvage the black box.
France has said the flight recorders from the plane, which went missing en route from Rio de Janeiro to Paris with 228 passengers and crew on board early on Monday, are unlikely to be found due to the extreme depth.
However, President Luiz Inacio Lula da Silva was quoted by the Globo daily as saying: "I think that a country that can produce oil at a depth of 6,000 meters will be able to find an airplane at a depth of 2,000 meters."
He said Brazil would continue "doing everything possible and impossible" to find the black box and the passengers' bodies.
Brazil's Air Force said on Tuesday it had found fragments of the wreckage floating in the area where that the plane last made contact.
The French Bureau for the Investigation of Air Accidents said the black boxes would probably not be found due to insufficient information the mountainous terrain of the ocean floor, and that the wreckage could have sunk to a depth of 3,000 meters.
"I am not very optimistic that we will be able to find the flight recorders," Paul Louis Arslanian told reporters.
France has sent a research ship with two mini-submarines to the area.
The debris was discovered around 650 kilometers (390 miles) north of Brazil's Fernando de Noronha archipelago. Before losing contact, Air France Flight 447 had sent an automatic signal to airline maintenance computers from the area, indicating several technical failures.
Lightning has been suggested as a possible cause of what, if confirmed, would be the worst civilian plane crash since 2001. However, French authorities are not ruling out terrorism.
The Brazilian Navy has dispatched five vessels to assist in the search effort. The operation also involves five planes, two Air Force helicopters and four commercial vessels.
