In a series of tweets on Friday, billionaire entrepreneur Mark Cuban challenged Donald Trump to an interview, offering to give $10 million to the charity of Trump’s choice if he could grill the Republican nominee on his policies for four hours.

Cuban has frequently taken to social media—and late-night talk shows—to taunt or criticize Trump throughout the presidential campaign. Cuban also said he would have considered being Hillary Clinton’s running mate.

Trump, who has faced scrutiny over following through on charitable donations, has not yet responded to the challenge. Cuban proposed a one-on-one detailed interview that makes no mention of Clinton.

“I’ll add an option. If you need it, I’ll write you the check and you can keep the money rather than give it to charity,” Cuban wrote on Twitter.

Get our Politics Newsletter. The headlines out of Washington never seem to slow. Subscribe to The D.C. Brief to make sense of what matters most. Please enter a valid email address. Sign Up Now Check the box if you do not wish to receive promotional offers via email from TIME. You can unsubscribe at any time. By signing up you are agreeing to our Terms of Use and Privacy Policy . This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. Thank you! For your security, we've sent a confirmation email to the address you entered. Click the link to confirm your subscription and begin receiving our newsletters. If you don't get the confirmation within 10 minutes, please check your spam folder.

Write to Katie Reilly at Katie.Reilly@time.com.