The country-of-origin labeling (COOL) law requires labels on packages of beef, pork, poultry and lamb sold in U.S. stores to carry specific information on the source of the meat. The U.S. terms it a "consumer information" program.
While favored by consumer groups, COOL has been a lightning rod for dispute for more than a decade. Congress approved meat-origin labeling in 2002, but it did not become mandatory until 2009.
The United States re-wrote the regulations this year in an attempt to satisfy a 2012 World Trade Organization ruling, but has been challenged again at the WTO.
At the first negotiating session on a final version of the new $500 billion U.S. farm bill, several lawmakers said COOL should be revised or repealed, in part because of the risk of international sanctions.
"I am hopeful that working together we can prevent the imposition of tariffs on a wide array of products important to many states," said House Agriculture Committee chairman Frank Lucas in an opening statement. Under congressional protocol, he chairs the farm bill talks.
Canada and Mexico say the law led to a decline in sales of their cattle and hogs because of additional costs to handle them. U.S. meatpackers say COOL is a bookkeeping headache that also drives up costs.
Defenders such as the National Farmers Union and the Consumer Federation of America say COOL help shoppers make informed decisions on their meat purchases. They said there is no need for Congress to intervene.
The U.S. Department of Agriculture says COOL is not a food safety or traceability program. Foreign food products must still meet U.S. food safety standards.
Republican Senator Pat Roberts from Kansas, one of the largest U.S. cattle states, said he would support a House provision that was under development and expected to be a repeal clause for COOL.
Senate Agriculture chairwoman Debbie Stabenow said COOL "clearly is one of the issues" for farm bill negotiators.
As the farm bill conference kicked off, negotiators, with a target of completing work before year-end, remain divided on potential cuts to food stamp funding, but are agree on many other elements of the legislation.
President Barack Obama last week listed the farm bill as one of three priorities for completion this year. The administration has not spelled out how it will take part in the bill's final stages.
