Mexico expanded the list of U.S. products subject to retaliatory tariffs as it steps up pressure on Washington to settle a long-running dispute that has kept Mexican long-haul trucks off U.S. roads.

The government of President Felipe Calderon was infuriated last year when U.S. lawmakers voted to cancel funding for a a pilot begun under U.S. President George W. Bush allowing long-haul Mexican trucks to circulate in the United States.

Under the North American Free Trade Agreement (NAFTA), which took effect in 1994, the United States agreed to open its market to Mexican trucks. Mexico said the United States was not living up to its end of the deal and retaliated by imposing duties on a long list of U.S. exports, including fruit, vegetables and industrial goods.

Mexico’s Economy Minister Bruno Ferrari said despite the clampdown on certain U.S. products, negotiations were still stalled, forcing Mexico to take new action.

“Mexico has not received a formal proposal to resolve this situation, which is affecting Mexican truckers and has hurt trade and competitiveness in North America,” Ferrari said.

“We are not delaying this any more. This cannot continue,” he told a news conference.

Mexico’s embassy in Washington said the revised list will include 99 products, up from 89 currently.

U.S. business groups say the dispute has threatened thousands of U.S. jobs and hit bi-lateral trade.

U.S. Transportation Department spokeswoman Olivia Alair said the agency was “developing a new proposal” that would meet U.S. commitments under NAFTA and address concerns raised in Congress about Mexican long-haul truckers.

“Mexico is an important U.S. export market and President Obama understands the economic pain that these tariffs cause for American farmers, companies and workers,” U.S. Trade Representative Ron Kirk said in a separate statement.

U.S. manufacturers and farm groups expressed frustration that Obama has taken so long to find a solution.

Congress terminated the trucking program on the basis of safety concerns, critics accuse lawmakers of bowing to protectionist pressures from the U.S. Teamsters union.

“The basic underlying issue has not changed in that the U.S. has violated the terms of a trade agreement and thousands of U.S. manufacturing jobs are at risk if the Administration and Congress don’t take the necessary steps toward compliance,” said Doug Goudie, director for international trade policy at the National Association of Manufacturers. (Reuters)