"He is holding up with strength and dignity," the Oscar and Tony winner, 41, said at the golfing world's Ryder Cup "Welcome to Wales" gala in Cardiff. "He is about to finish his treatment and the doctors could not be happier."
Prince Charles, also on hand at the for the international golf tourney, told Jones: "Give him my best. Healing thoughts," reports the Western Mail.
"Catherine said Michael was home rooting for the American team, while she is rooting for team Europe," a friend told People. "It keeps thing interesting!"
Zeta-Jones noted that bothshe and her husband are avid golf fans.
"Michael will be on Skype screaming for the Americans. He wishes he could be here."
Douglas, who turned 66 last week, was diagnosed with throat cancer in August. He is appearing in "Wall Street: Money Never Sleeps," the long-awaited sequel to "Wall Street," a 1987 film that landed him a best actor Academy Award.