(NEW YORK) -- Donald Trump slammed comedian Jerry Seinfeld for canceling an appearance at a benefit for his son's Eric Trump Foundation over the "birther" issue.
Seinfeld pulled out of a St. Jude Children's Hospital benefit because he disagrees with Trump's questioning of President Obama's citizenship, according to the New York Post.
"I just learned you canceled a show for my son's charity," said Trump in a letter to Seinfeld, "because of the fact that I am being very aggressive with respect to President Obama, who is doing an absolutely terrible job as our leader."
Trump also said Seinfeld's NBC show, The Marriage Ref was "absolutely terrible."
Seinfeld's rep said that the comedian "feels this kind of demagoguery has no place in public discourse" but is making a contribution to the charities.
Copyright 2011 ABC News Radio