The US has had its attempts to block an EU emissions tax expected to cost passengers £21 per flight thrown out by the European Court of Justice.
The move means airlines will face a green tax on flight emissions to and from all 27 EU countries from the beginning of 2012.
After the ruling the US state department said they still had "strong legal and policy objections": "We continue to have strong legal and policy objections to the inclusion of flights by non-EU carriers in the EU emissions trading scheme. We do not view the decision as resolving these objections."
Canada, America and China all object to the tax. It is expected the move will add £21 to passengers travelling to America and according to Thomas Reuters Point Carbon could add 9bn euros to costs for airlines in the next eight years.
But a spokesperson for the EU climate change commissioner said they planned to stand firm and would not "abandon nor delay" the tax.