Former President Jimmy Carter has advanced cancer

Former President Jimmy Carter says he has cancer that has spread, although it's not yet clear what kind of cancer he has.

NBC News reports the 90-year-old on Aug. 3 had a mass removed from his liver.

"Recent liver surgery revealed that I have cancer that now is in other parts of my body. I will be rearranging my schedule as necessary so I can undergo treatment by physicians at Emory Healthcare. A more complete public statement will be made when facts are known, possibly next week," Carter said in a statement.

Read more from NBC News.