The U.S. Navy will send one of its new P-8A Poseidon surveillance aircraft to join an older P-3 Orion in the search for missing Malaysia Airlines Flight 370, a spokesman for the Seventh Fleet said Thursday.

The P-8, a modified Boeing 737 that the Navy only started using late last year, is faster and has a much longer range than the propeller-driven P-3, which was sent to join the search on Saturday.

That capability could be crucial if the search extends further from the Malaysian coast following a Wall Street Journal report that U.S. investigators suspect Flight 370 stayed in the air for about four hours past the time it reached its last confirmed location.

The P-8, which is the U.S. Navy's most advanced antisubmarine and aerial reconnaissance aircraft, would move into the area on Saturday to join the search in a daily rotation with the P-3, said Seventh Fleet spokesman Cmdr. William J. Marks.

The P-8 has a maximum speed of 490 knots (or nautical miles per hour), a ceiling of 41,000 feet and provides a range of more than 1,200 nautical miles with four hours on station, he said. That's about 300 nautical miles further than the P-3.

For a search mission like this, the P-8 would typically fly at 5,000 to 10,000 feet at 350 knots, with a search time of about 8-9 hours, depending on distance to search area, he said.

"This move adds the P-8's enhanced technology and greater range to the search efforts while maximizing planned maintenance and guarding against air crew fatigue for both aircraft," the spokesman said.

The P-3 would fly a search mission on Thursday evening using its radar, infrared and night vision capabilities, he said.

He did not say where the P-8 was coming from, but the U.S. has deployed six of the new aircraft to Okinawa in southern Japan since December as part of its "rebalancing" strategy to shift more military assets to Asia.

Cmdr. Marks also said that one of the two U.S. destroyers involved in the search, the USS Kidd, was moving from the Gulf of Thailand to the Strait of Malacca and was expected to arrive there to continue the search in 24-48 hours.

"We do not have detailed information on her assignment in the Strait of Malacca at this time," he said.

The other U.S. destroyer, the USS Pinckney, was being sent to Singapore for planned maintenance and routine voyage repairs, he said.

"With the search area expanding into the Strait of Malacca, Pinckney is not currently needed until follow-on information is available and planning occurs. She will continue searching during her transit south today."

The Seventh Fleet had no information to corroborate reports of debris spotted by Chinese satellites, he added. China has released satellite images of what it says could be the crash site in an area off the southern tip of Vietnam, although it's not clear how strong the lead is.

-- Jeremy Page. Follow him on Twitter @JNBPage