Acting FBI Director Andrew McCabe said there has been "no effort to impede our investigation to date" during testimony Thursday in front of the Senate Intelligence Committee.
Sen. Marco Rubio (R., Fla.) asked McCabe if President Trump's firing of ex-FBI Director James Comey had "impeded, interrupted, stopped, or negatively impacted any of the work, any investigation, or any ongoing projects" at the FBI.
"The work of the men and women of the FBI continues despite any changes in circumstance, any decisions, so there has been no effort to impede our investigation to date," he said. "Simply put, sir, you cannot stop the men and women of the FBI from doing the right thing, protecting the American people, and upholding the Constitution."
Trump's firing of Comey has prompted criticism that he is attempting to interfere with federal probes into Russian meddling in the 2016 presidential election and allegations of collusion to that end with the Trump campaign.
Trump initially said he fired Comey due to a recommendation from his attorney general regarding Comey's mishandling of the Hillary Clinton email investigation, although the explanation has evolved. The Trump administration has argued the FBI needed fresh leadership and has staunchly defended the decision to terminate Comey.