As other ships headed toward the area to contribute to the search, the British Ministry of Defense told ABC News that the British HMS Echo, a hydrographic survey ship, had yet to leave the Persian Gulf and would not arrive for at least 10 days.
An Australian ship that has a remotely-operated mini-submarine was also joining the search, said Malaysian officials.
A small flotilla of ships from China is still several days away. The Malaysian plane passengers included 154 Chinese.
A Norwegian merchant ship that had been asked to divert from its planned course to help search the area was allowed to continue on its planned route to Melbourne, said the Australian Maritime Safety Authority.
Weather is adding further difficulty to the search efforts. A tropical storm is headed for the search area, Acting Australian Prime Minister Warren Truss said, with strong winds expected.
Satellite images released by Australia showed two objects – the biggest about 80 feet long – in the southern Indian Ocean. Those images were taken March 16, but the search in the area did not start until Thursday, March 20, because it took time to analyze the images.
Aircraft in the Indian Ocean included two ultra-long-range commercial jets and four P3 Orions, the Australian Maritime Safety Authority said.
Because of the distance to the area, the Orions will have enough fuel to search for two hours, while the commercial jets can stay for five hours before heading back to the base.
Malaysia – which is overseeing the overall search efforts – asked the U.S. for undersea surveillance equipment to help in the search, said Rear Adm. John Kirby, a Pentagon spokesman. Defense Secretary Chuck Hagel promised to assess the availability of the technology and its usefulness in the search, Kirby said.
The Pentagon says it has spent $2.5 million to operate ships and aircraft in the search and has budgeted another $1.5 million for the efforts.
There is a limited battery life for the beacons in the cockpit-voice and flight-data recorders — about 30 days, said Chuck Schofield, vice president of business development for Dukane Seacom Inc. He said it's "very likely" that his company made the beacons on the missing jet. The devices work to a depth of 20,000 feet, with a signal range of about 2 nautical miles, depending on variables like sea conditions. The signals are located using a device operated on the surface of the water or towed to a depth.
Experts say it is impossible to tell if the grainy satellite images of the two objects were debris from the plane. But officials have called this the best lead so far in the search that began March 8 after the plane vanished over the Gulf of Thailand on an overnight flight to Beijing.
Malaysian authorities have not ruled out any possible explanation for what happened to the jet but have said the evidence so far suggests it was deliberately turned back across Malaysia to the Strait of Malacca, with its communications systems disabled. They are unsure what happened next.
Police are considering the possibilities of hijacking, sabotage, terrorism or issues related to the mental health of the pilots or anyone else on board.
The Associated Press contributed to this report.