Sen. Bill Cassidy, R-La., said Thursday morning that talk show host Jimmy Kimmel doesn't have a full understanding of the healthcare bill that Republicans hope to pass next week, and only knows what Obamacare supporters are saying about it.

Kimmel on Wednesday night said Cassidy lied to him when he said a year ago that people with pre-existing conditions should be covered in any plan to revamp Obamacare.

Cassidy and other Republicans have a plan to send Obamacare funds to states as block grants, but Kimmel said the bill would not protect people like his son, who was born with congenital heart disease.

"It is by many accounts the worst healthcare bill yet," Kimmel declared on his show "Jimmy Kimmel Live!" on Wednesday.

But Thursday morning on Fox News, Cassidy said his proposal would protect those with pre-existing conditions, and that he has not talked to Kimmel about the new bill yet.

"So Jimmy doesn't understand, and not because he is a talk show host, but because we have never spoken," Cassidy said. "He has only heard from those on the Left who are doing their best to preserve Obamacare."

"He has not heard from me. We have not spoken and I would love to talk to him about this," Cassidy said.

He added that he was only on Kimmel's show a year ago, before this new proposal was developed.

Cassidy stressed that his bill would require the federal government to approve state-level healthcare plans, and could only do so if those plans ensured coverage for people with pre-existing conditions.

"The legislation says that nothing a governor asks for will be approved unless there is affordable and adequate coverage for those with pre-existing conditions," he said.