"We need to be smart, vigilant and tough," Trump tweeted on Saturday, hours after police confirmed reports of an incident in London. "We need the courts to give us back our rights. We need the travel ban as an extra level of safety."
"This piece of (expletive) is not just an embarrassment to America and a stain on the presidency," Aslan, who is Muslim, tweeted in response. "He's an embarrassment to humankind."
On Sunday, Aslan apologized for using profanity when describing Trump and deleted his offending tweet.
“I lost my cool and responded to him in a derogatory fashion. That's not like me," Aslan said. “I should have used better language to express my shock and frustration at the president's lack of decorum and sympathy for the victims of London. I apologize for my choice of words.”
Related: Donald Trump tweets 'We need the travel ban' amid reports of London terror attack
CNN Money reported that the network responded by saying, "We are pleased that he has apologized for his tweets. That kind of discourse is never appropriate."
Once news of the cancellation of his series was confirmed, Aslan tweeted the following statement Friday:
"Obviously I am very disappointed in this decision. 'Believer' means a great deal to me and to the countless viewers it's reached. Its message of religious tolerance and exploration is extremely important right now. I am deeply grateful to CNN for giving me the opportunity to launch the show and to amplify my voice on their network. I am especially grateful to the legion of people within the Turner organization who worked so hard to make the show a hit series.
"However, in these politically charged times, the tenor of our nation's discourse has become complicated, and I recognize that CNN needs to protect its brand as an unbiased news outlet. Similarly, I need to honor my voice. I am not a journalist. I am a social commentator and scholar. And so I agree with CNN that it is best that we part ways. I look forward to partnering with another platform in the future to continue to spread my message. I wish CNN all the best."
Aslan’s production company had already begun working on the second season of “Believer” when CNN said it would not continue production of the series. The second season was announced by the network in May.