The Republican said the city - once the birthplace of the US car industry, now groaning under $18bn (£12bn) of debt - deserves a fresh start.

Detroit has faced decades of problems linked to declining industry.

Public services are nearing collapse and about 70,000 properties lie abandoned.

Gov Snyder said the city had filed for bankruptcy on Thursday because it was "basically broke".

"Many people may step back and say this is the lowest point in Detroit's history," he told Friday's news conference. "The history books may say that.

"But what would happen if we didn't do this act?

"Detroit would continue to go downhill and it wouldn't be the lowest day in Detroit's history. They would continue day after day and that's not right, again for the citizens."

He added: "We will come out with a stronger, better Detroit and a format to grow this city. The citizens of not just this city but the state deserve it."

Gov Snyder was flanked by state-appointed emergency manager Kevyn Orr, who suggested last month that the city's long-term debt could be as high as $20bn.

Mr Orr will be allowed to liquidate city assets to satisfy creditors and pensions, if the bankruptcy filing at a federal court is approved.

Detroit - known as Motor City for its once-thriving automobile industry - stopped unsecured-debt payments last month to keep the city running.

Mr Orr proposed a deal in June in which creditors would accept 10 cents for every dollar they were owed. The city is currently paying 38 cents on the dollar.

But two pension funds representing retired city workers resisted the plan.

Ed McNeil, the lead negotiator for a coalition of 33 unions, told Reuters news agency the move was about "busting the unions".

"This is not about fixing the city's finances," he said. "It's about the governor and his own agenda to take over the city of Detroit."

US car company General Motors said on Thursday it did not expect any impact on its operations.

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The White House said it was closely monitoring developments in the Michigan city.

The city has struggled with its finances for some time, driven by a number of factors, including a steep population loss.

Just between 2000-10, the number of residents declined by 250,000 as people moved away.

The murder rate is at a 40-year high and only one third of its ambulances were in service in early 2013.

Police response times to 911 calls average 58 minutes, compared with 11 minutes nationally.

And Detroit's government has been hit by a string of corruption scandals over the years.

Detroit is only the latest US city to file for bankruptcy in recent years.

In 2012, three smaller California cities - Stockton, Mammoth Lakes and San Bernardino - took the step.