US President Donald Trump has scornfully rejected "disgusting" talk among Democrats about launching an impeachment inquiry against him in the aftermath of the Russia probe.
Special Counsel Robert Mueller said on Wednesday that his report on Russian collusion in the 2016 presidential campaign did not clear Trump of obstruction of justice.
Mueller indicated it was up to Congress to decide whether he should be impeached.
The statement fuelled an increase in calls from Democratic lawmakers for impeachment proceedings, and US House of Representatives Speaker Nancy Pelosi, reacting to Mueller's statement, said: "nothing is off the table".
Trump, who grew animated when reacting to Mueller's statement, was asked by reporters if he expected to be impeached.
"I don't see how ... it's a dirty, filthy, disgusting word ... it's a giant presidential harassment," he said at the White House on Thursday.
He cited the US Constitution's language that a president can be charged with "high crimes and misdemeanours."
"There was no crime. There was no misdemeanour," he said.
While House Democrats have yet to decide whether to pursue impeachment, they are pressing forward with a number of investigations spinning off from the Russia probe.
The Trump administration is fighting those congressional efforts, including an attempt to obtain the president's tax returns.
The top Democrat on the Senate Finance Committee, Ron Wyden, said on Thursday the US Treasury had been "unresponsive" to questions about Treasury Secretary Steve Mnuchin's decision not to comply with the House demand for Trump's returns.
Wyden threatened to attempt to block any Treasury nominees if the department was not forthcoming.
"Congress has a constitutional obligation to conduct oversight of the executive branch," he said in a statement.
In a morning tweet, Trump had left the impression he was acknowledging that Russian interference helped him win the 2016 election over Democrat Hillary Clinton. He later said the exact opposite.
"No, Russia did not help me get elected," he told reporters, adding that he needed no help in winning the election.
Trump heaped scorn on Mueller, calling him "totally conflicted" in part because he had wanted to head the FBI.
"I told him NO. The next day he was named Special Counsel - A total Conflict of Interest. NICE!" Trump said on Twitter, without providing evidence that Mueller, a Republican, had sought the FBI job.
Speaking to reporters, Trump also said that Mueller is a close friend of former FBI Director James Comey, who Trump fired weeks after taking office in early 2017.
"I think Mueller is a true 'never Trumper,'" Trump said.
