Martin Sheen encouraged Charlie Sheen to reveal he's HIV-positive for months

Martin Sheen praised his son Charlie Sheen's courage after he admitted he is HIV-positive on NBC's "Today" show Tuesday.

The "West Wing" actor was in Naples, Italy, on Tuesday attending the annual CME Group's Global Financial Leadership Conference, the Naples Daily News reported.

Martin said that the confession was a long time in the making, because Charlie had a hard time committing to his announcement.

"He had been leading up to this sort of story for several months, and we kept encouraging him to do it," Martin, 75, said at the conference. "And he kept backing away and backing away, because it was like going to his own execution, I guess."

Charlie, 50, told "Today" host Matt Lauer that he had been diagnosed with HIV about four years ago. And over the years, he had paid upward of $10 million to blackmailers threatening to expose that he contracted the virus.

"It was the most difficult thing he'd ever done," Martin said. "And he kind of sealed it when he called Matt Lauer last week and asked if he could go on."

Ahead of the interview, Charlie wrote an open letter expressing his feelings about his diagnosis and why admitting it was akin to "claiming back my freedom." Martin said that although he was a continent away, he was supporting his son.

"We didn't know until he walked on the set this morning that he was going to do it," Martin Sheen said. "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."

After the interview, Sheen's ex-girlfriend Bree Olson said he had not informed her of his HIV status. Sheen contended on "Today" that he had told every sexual partner about his status.