Democratic U.S. Rep. Chellie Pingree says she wants Congress to continue inquiries into President Donald Trump and to “move toward an impeachment inquiry.”

Pingree’s statement came after special counsel Robert Mueller spoke Wednesday about his investigation into Russia’s election meddling and contacts with the Trump presidential campaign.

Mueller said federal rules prevented him from charging the president with a crime. He also noted that he didn’t exonerate the president of obstruction of justice.

Pingree said it’s up to Congress to investigate whether the president obstructed justice in the Russia investigation. She also said the president’s “unwillingness to cooperate with Congress,” particularly on foreign election interference, is “an insult to our system of coequal branches of government.’