El Salvador is among a dozen nations that has been added to the U.S. Department of Labor's list of countries accused of using child or forced labor.
The agency fears that the worldwide economic crisis could lead to more exploitation of children and low-end workers.
Coffee grown in El Salvador is among 128 other products and resources in 70 countries from around the world where child labor, forced labor or both are used in violation of international standards.
"Shining light on these problems is a first step toward motivating governments, the private sector and concerned citizens to take action to end these intolerable abuses that have no place in our modern world," said Labor Secretary Hilda Solis.
It is the first time El Salvador has been on the list. Also new to the list are Angola, Central African Republic, Chad, Ethiopia, Lesotho, Madagascar, Mozambique, Namibia, Rwanda, Zambia and Zimbabwe.
The annual reports are not intended to punish or shame the countries where an estimated 215 million child laborers toil in factories, on farms or as domestic helpers. In fact, the agency says many of the countries that appear on the list are taking steps to address child labor problems.
Labor Department officials say making the public aware of the problem helps promote efforts to combat child labor.
While the total number of child laborers fell by about 3 percent from 2004 to 2008, the rate of decline has slowed in recent years.
"I think the very recent picture gives us significant cause for concern," said Sandra Polaski, deputy undersecretary for the Bureau of International Labor Affairs. "That has a lot to do with the economic crisis."
India remains home to the greatest number of child laborers, followed by China. But smaller nations in sub-Saharan Africa have a much higher proportion of children — up to one-third of children under 14 — who go to work instead of school each day.
For the first time, the reports include a set of proposed actions for each government to consider to help reduce the problems detailed.
The agency praises India and some other countries for working to address the problem through anti-poverty programs and compulsory education. Brazil, Thailand, Jordan, Ivory Coast and Ghana also win plaudits for their efforts to combat child labor.
At the same time, the report calls out some of the worst offenders. They include Uzbekistan, where local officials require children to pick cotton, and Myanmar, where forced labor of adults and children helps produce everything from sugar and teak to rubber and rubies.
"They know what the problem is and they know how to fix it, they just need to get serious about doing it," Polaski said.
The problem is complicated in countries like India, Pakistan and Tonga that have no legislation setting a minimum age for work. That makes children more vulnerable to being pulled into hazardous or grueling trades.
Some of the most common products produced by child labor or forced labor include cotton, sugar cane, tobacco, coffee, bricks, gold, diamonds and coal.
The Labor Department is also working to combat instances of child labor in the United States.
Last year, for example, investigators from the agency's Wage and Hour Division found children as young as 6 working on blueberry farms in Michigan. Eight farms were fined about $36,000 for violating federal migrant-housing and child-labor laws.
Solis said inspections this year during the harvest in Michigan, New Jersey and North Carolina have yet to find child labor violations.
Based on reporting by the Associated Press.