WASHINGTON — The chairman of the Federal Communications Commission has repeatedly said that ending the scourge of robocalls is a top priority. On Wednesday, he announced plans for the most aggressive action yet toward achieving that goal.

The chairman, Ajit Pai, proposed a rule that would empower mobile phone carriers to automatically block the unwanted calls, which often involve scams, by employing tools that filtered out calls from unidentified or unwanted callers.

The action would not stop all robocalls. The blocking technology can already be installed by consumers, and scammers have found some ways around it.

But the proposal could lead to wider use of the technology, which stops calls from numbers that do not appear on lists of numbers known to be legitimate.