U.S. President Barack Obama signed trade agreements with South Korea, Colombia and Panama into law on Friday.

Supporters say the deals will boost U.S. exports by billions of dollars and preserve or create hundreds of thousand of jobs in the United States. Opponents say the agreements will hurt rather than help American workers.

The agreements are a step toward Mr. Obama’s stated goal of boosting American jobs by doubling U.S. exports by 2015.

The deals got final congressional approval recently, four years after they were first negotiated during the administration of President George Bush. Republicans, who often get support from business interest, generally favored the free trade agreements. Many members of Mr. Obama’s Democratic party, which usually counts on union support, opposed the deals.

Mr. Obama re-negotiated parts of the deal with South Korea to help the U.S. auto industry, which helped him gain political support from some U.S. unions.

But the largest U.S. union organization says the deals will destroy rather than create U.S. jobs. The president of the AFL-CIO, Richard Trumka, also says the agreement with Colombia did not prevent the assassination of 51 union officials in Colombia over the past year.

The U.S. textile industry is expected to be hurt by the agreements, while U.S. exporters of meat, poultry, chemicals, plastics, and financial services are supposed to make gains.

The agreement with South Korea is the largest, but it must still be ratified by the South Korean National Assembly.