LA PAZ, Bolivia - Bolivia enacted a law Friday lowering the country's retirement age to 58, bucking a global trend in which countries push people to work longer to counteract the burden on national treasuries of rising life expectancy.

Critics say the law, which also nationalizes the pension system and generously extends coverage to the poor, is unsustainable.

Leftist President Evo Morales signed the bill surrounded by members of the powerful Bolivian workers federation, which helped draft the law.

Bolivia's current retirement age is 65 for men and 60 for women.

The law, which takes effect in a year, also extends pensions to the three million people - 60 percent of the working population - who labor in the informal economy as everything from street vendors to bus drivers.

"We are fulfilling a promise with the Bolivian people. We are creating a pension system that includes everyone," Morales said at the signing ceremony.

"Evo Morales thinks about the poor people, so they can have something for when they get old," said Juan Quispe, 45, a father of three who sells ice cream on the street outside the National Palace.

The new law will allow Bolivia's 70,000 miners to retire two years earlier - or as soon as age 51 if they have worked in life-sapping conditions deep underground. Mothers with more than three children will also get special treatment: the right to retire at age 55.

Morales, an Aymara Indian and the country's first indigenous president, grew up a dirt-poor llama herder and later went on to become a coca-growers' union militant.

The socialism he preaches is rooted in the communitarianism of his native culture. Since taking office in 2006, he has put this landlocked Andean nation's natural gas reserves, main phone carrier and electrical grid under state control.

Critics say the new law could breed financial disaster.

Jacob Funk Kierkegaard, an economist at the Peterson Institute in Washington, said that he knows of no other country lowering its retirement age.

"I would say that they are setting themselves up for a train wreck down the road," he said in a telephone interview. "That they should be willfully going down this road strikes me as very, very shortsighted."