In a setback for the Bush administration, a federal appeals court yesterday halted a federal plan to permit thousands of Mexican trucks on U.S. roads, calling instead for environmental reviews that could take up to three years. In November, President Bush approved the entry of 30,000 Mexican trucks per year, citing obligations under the North American Free Trade Agreement to lift trade barriers. A coalition of environmentalists, Teamsters, and U.S. trucking companies responded by filing suit, claiming the trucks would not meet U.S. emissions standards. The 9th U.S. Circuit Court of Appeals sided with the plaintiffs, saying that compliance with NAFTA “cannot come at the cost of violating United States law.”