US Republican presidential candidate Donald Trump at a campaign event at the Veterans Memorial Building in Cedar Rapids, Iowa, on Saturday. REUTERS/Scott Morgan Republican presidential front-runner Donald Trump slammed the fact-checking organization PolitiFact on Tuesday, calling the website "bad news."

PolitiFact, which has won a Pulitzer Prize for its 2008 election coverage, delved into Trump's various misstatements on Monday, when it awarded him "Lie of the Year" for what it called his "many campaign misstatements."

"It's the trope on Trump: He's authentic, a straight-talker, less scripted than traditional politicians," PolitiFact wrote. "That's because Donald Trump doesn't let facts slow him down. Bending the truth or being unhampered by accuracy is a strategy he has followed for years."

Trump was asked about the "award" on "Fox & Friends" on Tuesday, and he responded by calling PolitiFact a "left-wing group" that is "bad news."

"You can tell something 100% and they will make it out to a lie if you're a certain person," Trump said. "PolitiFact didn't like the idea that I said 'dancing on rooftops, dancing on streets,' but that's been confirmed by hundreds of people."

Trump was referring to his claim of Muslim-Americans celebrating the September 11, 2001, terrorist attacks in New Jersey after the Twin Towers fell, which has been widely scrutinized by fact-checkers.

At a November rally in Alabama, Trump said, "I watched when the World Trade Center came tumbling down. And I watched in Jersey City, New Jersey, where thousands and thousands of people were cheering as that building was coming down. Thousands of people were cheering."

PolitiFact rated this statement "Pants on Fire."

"There is no video of thousands of people in Jersey City cheering," the organization said. "Weeks later, Trump continues to stand by his claim but has not been able to point to evidence to back it up. Public safety officials on the ground in New Jersey say it never happened."

The Fox hosts asked Trump him about the backlash. They noted that NJ Advance Media investigated Trump's claims and found that while some people most likely did celebrate the 9/11 attacks, they didn't number in the "thousands," as Trump had said. NJ Advance Media found evidence of only "two modest celebrations" that amounted to dozens of people at two locations.

Trump said PolitiFact was missing his main point by focusing too much on the specific numbers.

"The only purpose in saying that was that there's something wrong," Trump said. "When you have people that are celebrating the fall of the World Trade Center ... [that] tells you there's something definitely going on here that's wrong. There's some bad stuff happening. And that's the point of the whole thing and that's how it started."

Fox also asked Trump about his claim that the Mexican government sends "bad" people across its border with the US. PolitiFact also rated this statement "Pants on Fire," noting that "there's no evidence to show the Mexican government encourages criminals to cross the border" and that most immigrants who enter the US illegally are seeking work.

But Trump stood firm in his assessment.

"The Mexican government, absolutely, in my opinion, pushes people over the border because we take anybody because we're run by stupid people and Mexico sends bad people over," Trump said. "There's no question about it."

Trump acknowledged that he wasn't referring to "huge percentages" of people, but he added, "We're talking about some very bad dudes are being sent over here because they don't want to take care of them, and I have no doubt about that."