President Trump was on Wednesday acquitted by the ruling Republican Party-controlled Senate on the two impeachment charges - abuse of power and obstruction to Congress.
On Tuesday, Pelosi publicly tore up her copy of Trump's annual State of the Union address, signalling the worsening relationship between the House Speaker and the US President.
“Well, I thought it was a terrible thing when she ripped up the speech. First of all, it's an official document. You're not allowed, it's illegal what she did. She broke the law,” Trump told reporters at the White House.
“But I haven't been asked the question other than a lot of people that viewed it, they couldn't believe that she did it. I thought it was terrible. I thought it was very disrespectful to the chamber, to the country,” he said.
Pelosi has been one of Trump's fiercest critics and the top Democrat was the one who first launched formal impeachment process in the House of Representatives against the president last year. President Trump has frequently taunted the 79-year-old lawmaker as "Crazy Nancy".
"I got very high marks for the speech and I didn't know she did it until I was walking out and some of the Congressmen and women were saying, 'Can you believe what she did? But I didn't know she did," he said.
Trump also slammed the Democrats, saying they were not constructive people.
"Well, I think there's a lot of evil on that side. They've gone crazy, they've gone totally crazy. It's too bad. I've got tremendous amounts of stuff, more than anybody's gotten done in three years by far. But they're not constructive people," he said.
"I do work with Democrats, I work with everybody but that group is, you know, they say 'Trump derangement syndrome'. They've got it. They've got a bad case of it. You saw that, that was on display the other night when she ripped up the speech. That was terrible, so disrespectful to our country and actually very illegal, what she did," he said in response to a question," Trump said.