KUALA LUMPUR - Malaysia will look at the possibility of deep-sea surveillance and salvage after the 30-day period when the black box of missing Malaysia Airlines flight MH370 stops emitting signals, said Malaysia's acting Transport Minister Hishammuddin Hussein.

Malaysia will continue to look for the black box even after the 30-day period, he told a daily press briefing on Friday.

The jetliner disappeared on March 8 with 239 passengers and crew members on board.

A US towed pinger locator and Bluefin-21 Autonomous Underwater Vehicle have arrived in Perth to assist with location and recovery of the black box flight data and cockpit voice recorders.

Planes and ships on Friday raced to a fresh search zone after a "credible new lead" that MH370 was flying faster than first thought before it plunged into the remote Indian Ocean.

Ten aircraft from six countries - Australia, China, Japan, New Zealand, South Korea and the United States - altered their flight paths to an area 1,100 kilometres north-east of where they have been looking for a week, far off western Australia.

The depth of the water in the search area is between 2,000 and 4,000 metres.

Mr Azharuddin Abdul Rahman, Head of Department of Civil Aviation (DCA), told reporters that the location of the new search area was based on complex calculations by Boeing and was within the southern corridor area earlier identified, but he declined to reveal the details.

The refinement in the search area is ongoing and is being conducted by experts.

He said the immediate focus is to get to the objects and to verify that they are from the missing plane.

When asked about the criticisms of Malaysia's handling of the crisis, Mr Hishammudin said Malaysia would not have done anything differently and that history will judge Malaysia as being "very responsible".

Malaysia has been consistent in not speculating on what happened to MH370 until evidence has been verified, he added.