When Charlie Sheen revealed he was HIV-positive on NBC's "Today" on Tuesday, his father Martin Sheen watched from a distance as his son revealed his secret to the world. Sheen says he hoped it would be the first day of a new life for his 50-year-old son.

The 75-year-old actor discussed his son at the eighth annual CME Group's Global Financial Leadership Conference in Naples on Tuesday, according to the Naples Daily News. Sheen said the family had been encouraging Charlie to go forward with the revelation but he kept backing away because it was like "going to his own execution." Martin said he admired his son for the courage he showed while admitting his illness to the world.

"I left him a message, and I said that if I had that much courage, I would change the world. This afternoon, I was still unable to reach him, and I left another message, that my favorite quote from Robert Kennedy was fulfilled with him today. Robert Kennedy once said, 'One heart with courage is a majority,'" Martin said.

Martin added that it was the most difficult thing Charlie ever had to do. He wasn't completely sure Charlie was going to make the revelation until he walked onto the "Today" set on Tuesday.

"I saw him Saturday night, my wife and I went to see him, to make sure he knew we were behind him, and if he wanted me to go, I would have canceled this event. He said, no, this was his and his alone," Martin said.

According to People, "The West Wing" star has been an activist in the fight against HIV and AIDS. He partnered with his other son, Emilio Estevez, at an AIDS fundraising event in 2010 in Toronto where they raised over $1 million.

The former "Two And A Half Men" star sat down with Matt Lauer on Tuesday morning to discuss his diagnosis and put a stop to any false rumors that were circulating about him. Charlie said that he hoped by telling his secret of being HIV-positive on national TV could go on to help others who might also be suffering from the virus.

"I have a responsibility now to better myself and to help a lot of other people and hopefully with what we’re doing today others may come forward and say, 'Thanks Charlie, thanks for kicking the door open,'" he said.

However, not everyone is speaking positively of Charlie. Ex-girlfriend and former "goddess" Bree Olson said Charlie never told her that he was HIV-positive, despite the fact that they were living together for over a year. Olson appeared on "The Howard Stern Show" Tuesday to set the record straight that she was HIV-negative and that she went out and got tested immediately after reports began to surface of Charlie's condition.

"He never said anything. I was his girlfriend. I lived with him. We were together. We had sex almost every day for a year," she told Stern.