"I am a young and dynamic man"

President Trump, 73, is described as "so young" on Friday, saying that compared to former vice president Joe Biden, 76, "I am a young and dynamic man . "

When asked about "how old is too old" to be president, Trump replied, "I am a young and dynamic man, I look at Joe, I do not know about him … I would never say that someone One is too old, they make me all look very young, both in terms of age and in terms of energy. "

[[[[Related: The 2020 candidates are too old, warns the former doctor of Obama: "We are asking for trouble"]

Biden entered the Democratic primary contest on Thursday. If he was elected, he would be the oldest president to have held a position – President Ronald Reagan was 77 years old, 349 days old at the end of his second term in 1989.

Biden, who turns 77 in November, tops most polls among Democratic candidates. Many polls show Senator Bernie Sanders, I-Vt., In second place. Sanders will be 78 in September.

"I would never say that anyone is too old, but I know that they make me all look very young, both in terms of aging and energy, I think, you know it better than anyone else" said Trump.