WARSAW (Reuters) - The United States criticized a decision by Poland’s media regulator to slap a $415,000 fine on TVN, a U.S.-owned private broadcaster, saying the ruling appeared to undermine media freedom.

The broadcaster was fined by regulator KRRiT on Monday over its coverage of protests in parliament last year.

“This decision appears to undermine media freedom in Poland, a close ally and fellow democracy. Free and independent media are essential to a strong democracy,” the U.S. Department of State said in a statement on Tuesday.

It added that it remained confident in the ability of Polish authorities to ensure democratic institutions were fully functioning and respected.

The regulator said it had fined the broadcaster’s TVN24 channel for “promoting illegal activities and encouraging behavior that threatens security,” without giving details.

TVN24 is the most widely watched independent channel in Poland, and critics on Monday interpreted the fine as an effort to mute its criticism of the ruling Law and Justice (PiS) party amid speculation the state may take the broadcaster over.

Since taking office in late 2015, the PiS has been at loggerheads with the European Union over policy, including placing the country’s media under increased state control.