Hillary Clinton said that the final presidential debate last Wednesday was the "last time" she had to share a stage to debate Donald Trump.

"I have now spent four and a half hours on stage with Donald, proving once again I have the stamina to be president," said Clinton during a rally in Pittsburgh, Pa., on Saturday. "You just have to be in a good cheer when you find yourself in a situation like that."

Trump openly questioned whether Clinton has the stamina to be president during the first presidential debate, and a campaign ad questioned her stamina while displaying images of Clinton stumbling during a Sept. 11 memorial ceremony. Her campaign later admitted that she had pneumonia at the time.

Clinton also took aim at Trump's answer at the third debate that he won't necessarily accept the results of the presidential election, saying he would keep the nation in suspense. Trump has repeatedly questioned the legitimacy of the election and questioned wehether it would be "rigged" in favor of his opponent.

"He is threatening the result of our democracy," Clinton said. "We know in our country the difference between leadership and dictatorship. Whether you support me or support my opponent together we must show that we support American democracy."