Donald Trump blamed an equipment malfunction for his failure to disavow the Ku Klux Klan and its former leader, David Duke.

The Republican presidential frontrunner appeared Monday morning on NBC's "Today" to explain his comments made the day before, when he told CNN's Jake Tapper he didn't know enough about Duke or the KKK to comment about the white supremacist's endorsement.

“Well, I have to look at the group,” Trump said. “I mean, I don’t know what group you’re talking about. You wouldn’t want me to condemn a group that I know nothing about. I’d have to look. If you would send me a list of the groups, I will do research on them, and certainly I would disavow if I thought that there was something wrong.”

NBC's Savannah Guthrie asked Trump to explain his comments, saying he had disavowed Duke's endorsement Friday but then said it would be "very unfair" to do so without examining the former KKK grand wizard and his views.

"I know who he is, but I never met David Duke, so when you talk about it, I never met David Duke," Trump said.

Guthrie reminded Trump that he refused to run for president on the Reform Party ticket in 2000 because Duke, who he dismissed as "a Klansman," was involved.

"The question was asked about David Duke and 'various groups,' and I don't know who the groups are," Trump said. "I said, would you do me a favor and tell me the groups? (Tapper) was unable to tell me that."

Guthrie said Tapper's questions referred specifically to Duke and the KKK, and Trump suggested he misheard the questions due to faulty equipment.

"Okay, let me tell you -- I'm sitting in a house in Florida, with a very bad earpiece that they gave me, and you could hardly hear what he was saying," Trump said. "What I heard was 'various groups.' And I don't mind disavowing anybody and I disavowed David Duke. And I disavowed him before at a major news conference."

Trump told NBC's Matt Lauer that CNN had been at that news conference and would have heard him disavow Duke.

"I have no problem disavowing groups but I'd at least like to know who they are," Trump said. "It would (not) be very fair to disavow a group, Matt, if the group shouldn't be disavowed. I have to know who the groups are. But I disavowed David Duke."

Trump said he had also disavowed Duke in a Facebook post.

"If you look at it, I disavowed David Duke all weekend long -- on Facebook, on Twitter, but obviously it's never enough," he said.

He said news reports about GOP efforts to derail his candidacy appeared to violate the pledge party bosses made to keep him from running a third-party campaign, and Trump said his "millions of followers" could help him hurt the Republican establishment.

"I could do something that would make them very unhappy," Trump said.

Watch the interview posted online by Today: