"I'm here to admit that I am HIV-positive," Sheen said. "And I have to put a stop to this onslaught, this barrage of attacks, subtruths, and very harmful, mercurial stories that are threatening the health of many others, which couldn't be farther from the truth."
The admission arrives after the National Enquirer first reported on Monday that the actor had contracted the virus. The tabloid also reported that the actor had risked the health of several sexual partners and others who didn't know he had the virus, including his former wives.
When "Today" anchor Matt Lauer asked whom he had told, Sheen answered, "Enough that I trusted to be in the position and the situation I am today." He said several people had blackmailed him for their silence and he had paid "enough to bring it into the millions."
"What people forget is that's money they're taking from my children," he said. "They think it's just me, but I have five kids and a granddaughter."
Sheen contended that he told all his sexual partners, including paid escorts, that he was HIV-positive. In turn, many of them threatened to tell the media about his diagnosis.
He also said it was "impossible" that he had passed HIV to anyone else. Sheen said two cases in which he acknowledged having unprotected sex after the diagnosis were "under the care of my doctor and they were completely warned ahead of time."
Sheen said he learned he had HIV four years ago after experiencing extreme migraine headaches and "sweating the bed." The actor said he was eventually hospitalized and thought he was suffering from a brain tumor.
"After a battery of tests, spinal taps, all that crap, they walked into the room and said, boom, here's what's going on," he recalled. "It's a hard three letters to absorb. It's a turning point in one's life."
Sheen, 50, has battled substance abuse and acknowledged having sex with prostitutes. When Lauer asked Sheen whether he had engaged in "risky behaviors" that led to contracting HIV, Sheen answered, "Negative ... you talking about needles, all that stuff? Definitely not."
When asked whether he knew how he contracted the virus, Sheen responded, "Sitting here today? Not entirely, no."
Matt Lauer of "Today" interviewing Charlie Sheen and his doctor Robert Huizenga about Sheen's HIV status.
Sheen's physician, UCLA assistant professor of clinical medicine Dr. Robert Huizenga, also appeared on "Today." He said Sheen's HIV was currently undetectable in his blood.
"Charlie has contracted the HIV virus," Huizenga said. "He was immediately put on treatment, strong antiviral drugs which have suppressed the virus — unfortunately, we don't have a cure yet — it suppressed the virus to the point that he is absolutely healthy from that vantage. And my biggest concern for Charlie as a patient is substance abuse and depression from the disease more than what the HIV virus can do in terms of shortening his life, because it's not going to."
Sheen said he no longer used drugs but still drank alcohol. He said he hoped acknowledging his HIV status would lead to the end of his drinking.
Huizenga also clarified that Sheen did not have AIDS.
"AIDS is a condition when the HIV virus markedly suppresses the immune system and you're susceptible to rare, difficult cancers and infections," the doctor said. "Charlie has none of those. He is healthy. He does not have AIDS."
He did say there was a small chance Sheen could pass the virus to sexual partners even if he continued his treatment and used protection. Sheen said he had never missed taking his medication over the four years since he learned of the diagnosis.
The former "Anger Management" star hopes he can help others with his admission.
"I have a responsibility now to better myself and to help a lot of other people," he said. "And hopefully with what we're doing today, others may come forward and say, 'Thanks, Charlie. Thanks for kicking the door open.'"
Amid the reports of Sheen's illness, "Today" sent a release to media outlets on Monday announcing that Sheen would make "a revealing personal announcement" on the show. More media sites were quick to confirm with sources that indeed Sheen had planned to speak on "Today" about contracting HIV.
Sheen's unpredictable behavior and public fights with "Two and a Half Men" cocreator Chuck Lorre led to his firing from the series in early 2011. He then went on to FX's appropriately titled "Anger Management" comedy for two years and 100 episodes. Most recently, he appeared on the "Ferris Bueller" episode of ABC's "The Goldbergs" in February.