House Intelligence Committee Chairman Adam Schiff (D-CA) said during a press conference Wednesday that President Donald Trump’s attack on an intelligence officer whistleblower amounts to an “incitement of violence.”

Schiff said during the press conference with House Speaker Nancy Pelosi (D-CA) that the president wants to characterize the intelligence officer whistleblower as “treasonous.”

“Let’s not make a mistake here, the president wants to make this all about the whistleblower and suggest that people come forward with evidence of his wrongdoing are somehow treasonous and should be treated as traitors and spies,” Schiff said.

House Democrats, including Schiff and Pelosi, have moved forward with an impeachment inquiry into Trump after he spoke with Ukrainian President Volodymyr Zelensky. During the call, Trump asked Zelensky about former Vice President Joe Biden’s son Hunter Biden and whether Joe Biden lobbied Ukraine to fire a prosecutor investigating Hunter Biden. Joe Biden reportedly threatened to withhold foreign aid to Ukraine if it did not fire the prosecutor.

After the conversation between Trump and Zelensky became public, Pelosi tapped Schiff to lead the impeachment inquiry.

“This is a blatant effort to intimidate witnesses; it’s an incitement of violence,” Schiff said.