Federal officials say the Americans are just trying to prolong the WTO process over Country Of Origin Labelling.
The U-S is seeking arbitration at the WTO on the amount of damages caused by the labelling rules.
Canada has formally requested WTO authority to impose retaliatory tariffs of more than 3 billion dollars a year on U-S exports because of the damages caused by COOL.
In a joint statement, Agriculture Minister Gerry Ritz and Trade Minister Ed Fast expressed disappointment with the U-S move.
The statement points out the USDA's Chief Economist estimates COOL is costing the American industry 2 point 6 billion a year.
The ministers say they are confident in their assessment that COOL is costing more than 3 billion dollars a year to the Canadian cattle and hog industries.
The statement reiterates the government's position that the only way the U-S can avoid retaliation by late summer is to ensure legislation repealing COOL passes the Senate and is signed by the President.