The US Congress will formally express its opposition to a European law aimed at reducing pollution from commercial jets, a thorny diplomatic issue that has threatened to escalate transatlantic trade tensions.
House and Senate negotiators have agreed to a provision in sweeping aviation legislation that would put Europe on notice over its mandate for airlines worldwide to pay for carbon emissions from their planes while flying to and from Europe.
The bill is expected to be passed by Congress in the coming weeks.
Compromise language expressing opposition to the law is less strident than a House-passed bill in October that sought to exempt US carriers entirely from the EU measure that took effect on January 1.
The modification is intended to align Congress with Obama administration sentiment and present a unified US position on the politically charged environmental controversy.
Airlines say the EU law amounts to a new tax at a time when they are wrestling with historically high fuel costs and softening demand for domestic flights.
China, India and other countries have called the EU law a violation of sovereignty.
Europe has said any congressional action over the law could harden diplomacy on both sides of the Atlantic and potentially lead to a trade fight.
Members of an EU delegation to the United States were scheduled to meet this week with State Department officials to review the latest developments.
A US State Department spokeswoman would not comment on recent correspondence from the EU delegation to US officials.
Transportation Secretary Ray LaHood, however, said on Tuesday that there "are a lot of discussions going on" and "we need to continue to talk to them."
LaHood called the EU law a "very bad scheme" for airlines.
"I've told my colleagues (in Europe) that Congress is very upset," he said.
US-based carriers affected by the EU policy are American Airlines, US Airways, United Airlines and Delta Air Lines. US carriers have raised fares to cover costs of complying with the change.