China will join the search for missing Malaysia Airlines Flight MH370 by sending a sonar vessel to the search area in the southern Indian Ocean, Australia's Deputy Prime Minister Warren Truss said on Friday.

Flight MH370 disappeared with 239 people on board during a flight from Kuala Lumpur to Beijing in March 2014, sparking one of the greatest mysteries in aviation history.

The Chinese vessel Dong Hai Jiu 101 was offered to Australian Prime Minister Malcolm Turnbull in November and will be deployed to join search operations in the southern Indian Ocean, where the plane is believed to have gone down, Truss said.