But Australian authorities said unidentified material washed up on the coast of Western Australia was being investigated for possible links to the missing Malaysian Airlines flight.
Australian Prime Minister Tony Abbott had earlier acknowledged the search strategy could change if seabed scans taken by the US Navy drone failed to turn up a trace of the plane, which went missing on March 8 with 239 people on board.
"We may well re-think the search but we will not rest until we have done everything we can to solve this mystery," he said.
"The only way we can get to the bottom of this is to keep searching the probable impact zone until we find something or until we have searched it as thoroughly as human ingenuity allows."
The Bluefin-21 drone, a key component in the search after the detection of audio signals believed to be from the plane's black box flight recorder, is due to end its first full mission in the southern Indian Ocean within days.
The finding of material on the southern tip of Western Australia was the first report of suspected debris in weeks and the first since the detection of what were believed to be signals on April 4.