Republican U.S presidential nominee Donald Trump escalated his attacks on Hillary Clinton Saturday suggesting that she might not be mentally fit to be president.

“She took a short-circuit in the brain. She’s got problems,” Trump reportedly said during a campaign rally in New Hampshire, taking a dig at Clinton’s Friday comment that she “short-circuited” when she tried to clarify certain statements regarding her use of a private email server.

“Honestly, I don’t think she’s all there,” Trump said.

At another rally in Iowa, Trump accused the former Secretary of State of being “unbalanced” and called her a ”dangerous” and “pathological” liar. He warned voters that if Clinton becomes president, it would lead to “the destruction of this country from within.”

“Unstable Hillary Clinton, lacks the judgment, temperament and moral character to lead this country — and I believe that so strongly,” he reportedly told his supporters, “She’s really pretty close to unhinged, and you've seen, you’ve seen it a couple times. The people in the background know it, the people who know her know it and she's like an unbalanced person.”

At his Wisconsin rally Friday, Trump called Clinton a “weak person.” “In one way she’s a monster,” the real estate mogul said, “In another way she's a weak person. She's actually not strong enough to be president.”

While Trump has been attacking Clinton’s character, former acting head of CIA Michael Morell wrote in an editorial in the New York Times on Friday that Trump “is not only unqualified for the job, but he may well pose a threat to our national security.”

“The character traits he has exhibited during the primary season suggest he would be a poor, even dangerous, commander in chief,” he wrote, “These traits include his obvious need for self-aggrandizement, his overreaction to perceived slights, his tendency to make decisions based on intuition, his refusal to change his views based on new information, his routine carelessness with the facts, his unwillingness to listen to others and his lack of respect for the rule of law.”

He added that Trump as a candidate is already damaging national security.

Green Party candidate Jill Stein warned voters against seeing Clinton as the “lesser of two evils,” saying that to vote for her would be a “losing strategy.”

Stein, who accepted the Green Party nomination during the party’s convention Saturday, reportedly said in her acceptance speech, “Hillary Clinton is the problem, she is not the solution to Donald Trump. We are the solution. We are the ones we've been waiting for.”