Malaysian, Chinese and Australian ministers will meet in Kuala Lumpur on Friday to discuss the future of the search for MH370, which disappeared during a flight from the Malaysian capital to Beijing in March 2014, carrying 239 people.
Almost A$180 million ($135 million) has been spent on an underwater search spanning 120,000 kilometres square in the southern Indian Ocean, the most expensive in aviation history.
Jacquita Gonzales, the wife of MH370 steward Patrick Gomes, said China and Malaysia had not contributed enough to the search effort, which is coordinated by the Australian Transport Safety Bureau.
"China, you could do more. I'm sorry for being so frank but you have the most at stake here," she said at a news conference. Most of the passengers aboard MH370 were Chinese nationals.
"(Malaysia), you need to do your bit and not just say 'I'm so sorry, we're short of funds, there's nowhere else to search'," Gonzales said.
KS Narendran, whose wife was a passenger on MH370, called on the Malaysian government to seek help in securing funding.
"This country and its leadership have wealthy friends. And I suppose therefore, there really should be no argument for a paucity of funds," he said.
The three governments had previously agreed that unless any new credible evidence arose, they would not extend the search which was originally scheduled to end in June but has been hampered by bad weather and is expected to resume in December.