Justin Bieber** is taking the high road.

After TMZ posted pictures of him smoking what appears to be marijuana, the "Beauty and the Beat" singer took to Twitter to address his millions of fans.

"Everyday growing and learning. Trying to be better. U get knocked down, u get up," the 18-year-old pop star wrote on the micro-blogging site Jan. 5. "I see all of u. I hear all of u. I never want to let any of you down. I love u."

Bieber didn't address the pot-smoking pics directly, but he did allude to facing "new challenges" and "new doubters."

"I'm ready. We are ready. See u all tomorrow and everyday after that," he tweeted. "Back on tour tomorrow. Ready to see u all smile. Time to do what I'm supposed to be doing. Performing."

It's been an interesting week for the teen idol, to say the least. Earlier, a paparazzo was killed while trying to photograph the singer's Ferrari in Los Angeles. Bieber was not in the vehicle at the time but expressed his condolences for the photographer's loved ones in a statement.

"While I was not present nor directly involved with this tragic accident," he said, "my thoughts and prayers are with the family of the victim."

This article originally appeared on Usmagazine.com: Justin Bieber Speaks Out Amid Marijuana Controversy: I'm "Trying to Be Better"