"No matter where you are in this universe, you will always be, my brother," he wrote.
He also shared a photo of himself sitting next to his late pal on Instagram, with the phrase "Brotherhood has no limits" above the pic.
Actress Jordana Brewster, who played Walker's onscreen love interest, also posted a photo of the actor on Instagram, and offered up a quote by writer Ralph Waldo Emerson as her tribute.
"The largest part of his power was latent," she wrote. "This is that which we call Character, a reserved force which acts directly by presence, and without means. #paulwalkerforever."
Tyrese Gibson shared a equally touching tribute to his co-star on Instagram, writing, "It's still not easy... 2 years ago today... We lost our brother... Today I'm just gonna lay low and process. Clarity through Prayers and perspective is what I always seek and pray for.
"With a heavy heart I post this... Please continue to pray for the Walker family and his real friends who was (sic) with him every single day... They're some of the best and strongest people I know... I know you're in heaven smiling and rooting for us all."
The second anniversary of Walker's death comes just days after the actor's father filed a wrongful death lawsuit against Porsche bosses, claiming insufficient safety equipment in the car in which he was a passenger in was to blame for his son's death and not the accident itself.
- WENN