During a meeting of the Senate Commerce, Science and Transportation Committee this week, LaHood called the EU's proposal "lousy." Under the proposal, which is similar to cap-and-trade proposals environmentalists once proposed in the United States, airlines from any country would have to trade credits for pollution emitted by flights to European destinations.
The plan applies the requirement to the entire length of the flight, not just the time an airplane spends over European countries, which the U.S. aviation industry has said is unfair. The EU's goal is for airlines to reduce their emissions from 2006 levels by 3 percent by 2013 and 5 percent by 2020.
A bill has been filed in the Senate to block the EU from applying the emissions trading requirement to U.S. airlines, and a similar measure measure has already been approved by the House.
LaHood said during the hearing earlier this week that he agrees with the opposition to the EU's emission rules, but he said the Department of Transportation does not endorse pending legislation.
Isakson argued in his letter Friday that LaHood would find "significant bipartisan support" for a filing a complaint with the ICAO, which the secretary said during Wednesday's hearing was the organization that should be regulating issues involving international air travel.