The United States has expressed its “deep concern” about what it called the “continued trend of restricted freedom of expression” in Russia, after Russian authorities limited access to the messaging app Telegram.

Harry Kamian, the new U.S. charge d’affaires of the United States to the OSCE, made the comments in a statement delivered on April 19 to the OSCE Permanent Council in Vienna, three days after Russian media regulator Roskomnadzor started blocking access to Telegram.

The move followed a court ruling against Telegram last week and a monthslong standoff between the popular messaging app and the Federal Security Service (FSB), which demanded access to its users' messages.

Kamian said that as an OSCE participating state, Russia should allow “free media and freedom of expression without undue government interference.”

He said that the United States supports the OSCE representative on freedom of the media’s call on Russian authorities to reconsider the restrictive measures against Telegram and to “promote a free, independent, and diverse communications environment.”

In a statement on April 13, the OSCE representative, Harlem Desir, said the decision to block Telegram “hampers the important role of Internet intermediaries in facilitating the exercise of the right to freedom of expression.”

The move to block Telegram has deepened concerns that the Russian government is seeking to close avenues for dissent as President Vladimir Putin heads into a new six-year term.