LOS ANGELES — Chris Brown issued a public apology Monday for his arrest earlier this year when he beat his girlfriend, fellow R&B star Rihanna.

"Since February my attorney has advised me not to speak out even though ever since the incident I wanted to publicly express my deepest regret and accept full responsibility," Brown says in a video message posted on his official Web site. "I felt it was time [that] you hear directly from me that I am sorry."

"I cannot go into what happened, and most importantly am not going to sit here and make any excuses," the 20-year-old singer continues. "I take great pride in me being able to exercise self control, and what I did was inexcusable. I am very saddened and very ashamed of what I have done. My mother and my spiritual teachers have taught me way better than that."

Brown says he has done a lot of soul searching over the last few months, in addition to talking with his mother and preacher.

"I spent a lot of time trying to understand what happened and why," he says. "I have let a lot of people down, and I realize that."

Last month, Brown pleaded guilty to one count of felony assault for the beating. The plea deal kept him out of jail, but the "Kiss Kiss" singer received a five-year probation sentence, six months of community labor, orders to complete domestic violence classes, and fines.

Brown was also ordered to stay at least 50 yards away from the 21-year-old Rihanna, except at industry functions where the minimum distance is 10 yards.

"As I sit here today I can tell you that I will do everything in my power to make sure that it never happens again, and I promise that. What I did was unacceptable, 100 percent," Brown says at the end. "I can only ask and pray that you forgive me, please. I hope that others learn from my mistakes. I intend to live my life so that I am truly worthy of the term 'role model.' "