Special Prosecutor Robert Mueller in a prepared statement Wednesday said there were multiple, systematic efforts to interfere with the 2016 presidential election by Russian operatives, and while there was insufficient evidence to allege a conspiracy that included the Trump campaign, he declined to exonerate the president on obstructing his investigation.

The special counsel made his comments at 11 a.m. ET from the Department of Justice, and from the outset made clear his statement would be his only public comment and that the report he submitted to Attorney General William Barr in April was his testimony, and should speak for itself.

Mueller outlined the purpose and intent of the two-part 448-page investigation that took nearly two years to complete, then explained long-established DOJ policy that prohibited the prosecution of a sitting president. As such, from the outset, the investigation did not seek to end in a prosecution of the president by DOJ.

In the roughly nine-minute statement, Mueller declined to clear President Trump of obstruction of justice and said the Constitution requires a process other than the criminal justice system to hold a president accountable, laying next steps squarely before Congress, and hinting at the possibility of an impeachment proceeding.

“If we had had confidence that the president clearly did not commit a crime, we would have said so,” Mueller said. “We did not, however, make a determination as to whether the president did commit a crime.”

While Mueller’s statements closely followed those already made public through his report, he stressed the gravity of the inquiry, where Barr has mostly played down the findings. He added the evidence uncovered by his investigation was a threat to our political system and “deserves the attention of every American.”

Mueller also said he was grateful to the Attorney General for releasing much of the report, but has previously objected to the way Barr portrayed the report’s findings, particularly Barr’s characterization that the report cleared the president of obstruction of justice allegations. Previously released excerpts of the report identified and detailed 11 instances wherein investigators found deliberate efforts to potentially obstruct the investigation.

“When a subject of an investigation obstructs that investigation or lies to investigators, it strikes at the core of their government’s effort to find the truth and hold wrongdoers accountable,” he said.

Mueller has said before and reiterated on Wednesday, he is reluctant to testify before Congress, as the Judiciary Committee has requested. He added his statement today ended his tenure at DOJ and he would be returning to civilian life.

Judiciary Chair Jerrold Nadler, D-N.Y., in a statement said Mueller did not exonerate the president and the Constitution “points to Congress to take action to hold the President accountable.”

Nadler added, “Although Department of Justice policy prevented the Special Counsel from bringing criminal charges against the President, the Special Counsel has clearly demonstrated that President Trump is lying about the Special Counsel’s findings, lying about the testimony of key witnesses in the Special Counsel’s report, and is lying in saying that the Special Counsel found no obstruction and no collusion.”

Nadler stopped short of calling for the start of an impeachment proceeding, despite many House Democrats and a single Republican, Rep. Justin Amash, R-Mich., have said they are ready to begin the process. Speaker of the House Nancy Pelosi, D-Calif., also has been reticent to engage impeachment at this time. Such a proceeding, while likely to be successful in the House, would encounter a Republican-controlled Senate and would stop there, essentially leaving House efforts twisting in the wind.

Sen. Elizabeth Warren, D-Mass., tweeted “It should be clear to anyone who read the report: Congress must hold the President accountable.”

President Trump, however, tweeted, “Nothing changes from the Mueller Report. There was insufficient evidence and therefore, in our Country, a person is innocent. The case is closed! Thank you.”