Following the phone call, a Downing Street spokesperson said:
A short time ago the Prime Minister called the Malaysian Prime Minister, Najib Razak, to discuss the investigation into missing flight MH370.
David Cameron said his thoughts are particularly with the relatives of those on board.
Prime Minister Najib thanked him and said it remained a very difficult ongoing operation. He appreciated the support of the Air Accidents Investigation Board and the satellite data provided by Inmarsat.
The Prime Minister offered other support if required, for which Prime Minister Najib thanked him. They agreed to keep in touch on the issue as necessary.