WASHINGTON -- US President Donald Trump said on Monday that he won't be watching former special counsel Robert Mueller testifying before congressional panels later this week.

"I'm not going to be watching. Probably, maybe I'll see a little bit. But I'm not going to be watching Mueller because you can't take all those bites out of the apple," Trump told reporters at the White House.

Mueller is set to testify publicly before the House Judiciary and Intelligence Committees on Wednesday and answer questions from lawmakers about his probe into alleged Russian interference in the 2016 US presidential election and possible obstruction by Trump.

The president also accused Democrats running the hearings of "wasting their time."

The remarks came hours after Trump renewed his attacks on Mueller and the Russia investigation that the former special counsel had led for nearly two years.

Mueller wrapped up his investigation in March by submitting a report to William Barr, who became Attorney General about a month earlier.

The report stated that there was no evidence that Trump's campaign conspired with the Russian government during the 2016 election but didn't conclude if the president had obstructed justice.

Instead, Mueller recounted 10 episodes involving Trump and discussed potential legal theories for connecting these actions to elements of an obstruction offense.

It was the Department of Justice that concluded that Mueller did not have "sufficient" evidence to support a charge in the obstruction case, a decision that has drawn scrutiny from Democrats, who have called for more investigations.