The long wait is taking a toll on family members of the passengers and crew of the missing Malaysia Airlines (MAS) plane which dropped off the radar over 30 hours ago.

Many were clearly distraught over what could have happened to their relatives on flight MH370, with MAS officials unable to provide new information beyond the promise that the national carrier has arranged for their transport to Vietnam once the missing aircraft is confirmed discovered.

The Prime Minister's wife, Datin Seri Rosmah Mansor, paid a visit to the families, who are now placed at the Everly Hotel in Putrajaya, to express her sympathy.

She advised them to be patient and remain strong and assured them that the authorities are doing as much as they can.

"They need to verify all the information they tell you. I'm sure they will let you know as soon as they get a confirmation,” she was heard saying to a grief-stricken mother.

The meeting session then continued with a short briefing behind closed doors of which members of the press were requested to leave.

MH370, a code share flight with China Southern Airlines, left KLIA for Beijing at 12:41am on Saturday morning.

All communication with the plane was lost at 2:40am and no distress signal or call was received.

The plane was carrying 239 passengers, 38 of them Malaysians. It was scheduled to arrive at the Beijing International Airport at 6:30am local time.