He told politicians that since he took over as acting attorney general in November 2018, there has been no change in the "overall management" of Special Counsel's Robert Mueller investigation.
Rep. Doug Collins, R-Ga., tried to adjourn the hearing before it started, saying it was an attempt at assassinating Trump's character.
"Bring your popcorn", he said.
Under questioning by Nadler, Whitaker proved combative and sought to dodge questions about his conversations with Trump and his top advisers, citing long-standing policy against disclosing details of such discussions.
Whitaker had threatened not to show up to the hearing after Democrats approved a subpoena if he didn't answer all their questions, but the committee chairman dropped the threat Thursday night. He added that he has not denied any funds to the special counsel's investigation. Democratic Caucus Chairman Hakeem Jeffries later railed at Whitaker.
"But you wouldn't oversee a witch hunt, would you?" By joining with Republicans in support of Barr's nomination, Senate Democrats could hand the new attorney general a powerful mandate to handle the eventual results of the Mueller investigation according to that pledge.
Why is Mr Whitaker controversial?"The Department of Justice must be such a place".
"Mr. Attorney General, we're not joking here, and your humor is not acceptable", Jackson Lee said.
"Have you ever been asked to approve any request or action to be taken by the special counsel?"
However, he said, "I have not spoken to the president about the special counsel's investigation".
Germany to not exclude Huawei from 5G networks
It will take 3 to 5 years for Huawei to deal with security issues raised by the UK's National Cyber Security Council (NCSC). It is likely that Trump may sign an order banning use of Chinese telecom equipment in USA networks citing security issues.
"I can assure you [Barr] has a very high opinion of Mr. Mueller and he is committed to letting Mr. Mueller finish his job", Republican South Carolina Sen.
Whitaker responded that he had been told by ethics officials that "the decision was mine to make based on the regulations of the Department of Justice, and I made that decision and I stand by that decision".
"Do you agree with the president's characterization of the Department of Justice and the Federal Bureau of Investigation?" she asked.
Whitaker also says he has not talked to President Donald Trump or senior White House officials about the investigation.
Whitaker said he'd read the memo. Here's one: Trump's acting attorney general involved in firm that scammed veterans out of life savings. He criticized the committee for prematurely and unnecessarily authorizing a subpoena for him even though he had agreed to appear.
"I remain willing to appear to testify tomorrow, provided that the chairman assures me that the committee will not issue a subpoena today or tomorrow, and that the committee will engage in good faith negotiations before taking such a step down the road", Whitaker said in a statement.
On Thursday evening, Nadler said no subpoena would be issued if Whitaker appeared before the committee Friday prepared to answer questions.
Raising his voice, Raskin cut off Whitaker before he could continue.
He said his comment at an unrelated news conference last week that the Mueller investigation was close to wrapping up - a remark that generated significant attention and speculation - reflected only "my position as acting attorney general".
"Ultimately, the decision whether or not to recuse was my decision". Jerry Nadler (D-N.Y.) pressed Whitaker about Mueller's probe.
"The Democrats in Congress yesterday were vicious and totally showed their cards for everyone to see", Trump tweeted Saturday morning.