Trump blasts Jimmy Carter with fiery response after he claims Trump's election not legitimate

President Donald Trump has fired back at Jimmy Carter, one day after the former president questioned the legitimacy of Trump's presidency.

Following the G-20 Summit in Japan on Saturday, Trump called Carter "the forgotten president" who is remembered for being a "terrible" leader "trashed" by his own party.

"Look, he was a nice man. He was a terrible president. He's a Democrat. And it's a typical talking point. He's loyal to the Democrats. And I guess you should be," Trump said, according to the Associated Press.

"He's been badly trashed," Trump later said. "He's like the forgotten president. And I understand why they say that. He was not a good president."

The president also refuted Carter's assertion that his presidency is illegitimate, telling reporters he earned the White House because he campaigned better than Hillary Clinton.

"Everybody now understands that I won not because of Russia, not because of anyone but myself," Trump said. "I went out and campaigned better, smarter, harder than Hillary Clinton."

Carter claimed Friday that Trump only defeated Clinton in 2016 because Russians interfered in the election on his behalf. He further asserted that if Russia interference were investigated fully, it would prove that Clinton was the rightful winner of the election.