Prime Minister Tony Abbott says there is nothing the federal government could have done to prevent the closure of Toyota and the end of car manufacturing in Australia.
Mr Abbott again described the loss of the car maker as devastating, but said there would be "better days ahead" for auto workers.
The world's largest car maker announced it would stop building cars in Australia by the end of 2017 - a decision that will cost 2500 jobs among the 4000 employed by Toyota in Australia, and hundreds more among parts makers and other suppliers.
Coming after similar announcements by Holden and Ford, Labor has now blamed the Abbott government for the impending end of local car manufacturing.
But the prime minister said he had on Monday night spoken to Toyota management, who told him they had looked "long and hard" at the closure and the decision was very considered, and final.
"It's not as if the government could have leapt in at the eleventh hour and said here's another hundred million or two hundred million dollars, please, please stay," Mr Abbott told ABC Radio on Tuesday.
"We've tried that with the motor industry.
"It hasn't worked, and the best thing now is to focus on things that we can do and which are profitable."
The opposition says the Victorian economy may take 20 years to recover from the closure of the Toyota plant at Altona, with industry spokesman Kim Carr comparing it to the economic woes of the 1930s.
"There's likely to be, for many blue collar Australians, an economic crisis the like of which we haven't seen since the Great Depression," Senator Carr told ABC radio on Tuesday.
"There are going to be families that won't be able to get work. There will be whole communities that will be savaged by this decision."
Mr Abbott admitted he couldn't offer Toyota workers "false hope" and the transition into new jobs is not always easy.
But he said other cities and regions that had gone through significant economic changes, such as Newcastle in NSW, which lost its steel works in the 1990s, have emerged as better places.
He said the government was working to make the economy as strong as possible to ensure Toyota workers could move to better jobs in the months and years ahead.
But when asked what those new jobs would be, the prime minister said: "I can't give you that answer.
"None of us know the answers to those questions.
"What we've got to do is remember that we are creative people in a capable country who have always faced the future with confidence and have always made the most of it."
Victorian Premier Denis Napthine will fly to Canberra on Tuesday to seek support for workers left jobless by Toyota's decision.
Mr Abbott said he would discuss with Mr Napthine how to create jobs through infrastructure and other projects the commonwealth is not yet involved in but could fund in the medium term.
"So the people of Victoria are confident that ... their state is going to be in better shape in five years time than it is now," the prime minister said.
Labor MP Tim Watts, whose electorate of Gellibrand includes Toyota's Altona plant, said he was furious.
"I am angry that Toyota workers had to go home to their families last night and over dinner tell them that they wouldn't have a job in the future," he said.
These jobs would not have been lost under a Labor government, he said.
"A Labor government would have shown leadership when this perfect storm hit the Australian manufacturing industry."
