U.S. airlines are suing to block the Biden administration from requiring greater transparency over fees that the carriers charge their passengers, saying that a new rule would confuse consumers by giving them too much information during the ticket-buying process.

The U.S. Transportation Department said Monday it will vigorously defend the rule against what it called “hidden junk fees.”

President Biden is expected to highlight his push to cap junk fees in his State of the Union address, for a second year in a row. It's a theme he plans to take on the campaign trail.

The Consumer Financial Protection Bureau issued a new rule Tuesday capping late fees on credit cards, a move designed to save customers an estimated $10 billion a year. Critics promised a lawsuit.

After President Biden called out "junk fees" in his State of the Union address, ticket vendors said they were willing to do more to disclose hidden fees. Live Nation is the latest to join.