Former Republican U.S. senator Rick Santorum has been dropped as a senior political commentator by CNN after remarks he made about Native American culture drew criticism.

Santorum gave a speech in April at an event of a conservative organization named the Young America's Foundation where he said:

"We birthed a nation from nothing. I mean, there was nothing here. I mean, yes, we have Native Americans, but candidly there isn't much Native American culture in American culture."

CNN, which came under pressure to drop him as a commentator after the remarks, said on Saturday it had parted ways with Santorum.

"When I signed on with CNN, I understood I would be providing commentary that is not regularly heard by the typical CNN viewer. I appreciate the opportunity CNN provided me over the past 4 years," Santorum said later on Twitter.