Mexico City, Mexico - The United States is not respecting a World Trade Organization (WTO) ruling on meat labeling, and it's hurting local industry, Mexico's Agriculture Minister Enrique Martinez said on Tuesday.

The WTO ruled in late June last year that a US program for labeling imported meat unfairly discriminated against Mexico and Canada, putting pressure on the United States to bring the scheme in line with global country-of-origin meat-labeling rules.

"We can't understand why once the very WTO issues a ruling, the government of the United States does not respect it," Martinez said.

"We have talked with beef producers in the United States and Canada, and totally agree this is an arbitrary decision and means discrimination against Mexican beef, which we will never agree with - and as a government will defend against."

Meat exporters in Canada and Mexico say the new rules would cut even deeper into cattle and hog shipments that have already slumped by as much as half in the last four years.

The Canadian government has threatened a possible retaliatory strike against US imports, and is hoping Mexico will join it.

The WTO Appellate Body said last year that United States "country-of-origin labeling rules," commonly known as COOL, were wrong because they gave less favorable treatment to beef and pork imported from Mexico and Canada compared to US meat.

Meat labels became mandatory in March 2009 after years of debate. US consumer groups and some farm groups supported the requirement, saying consumers should have information to distinguish between products from the United States, and foreign products.