Loving farewell from Robin Williams' daughter Zelda

"I love you. I miss you. I'll try to keep looking up."

With three simple sentences, Zelda Williams offered a heartfelt farewell to her father Robin, taking to Twitter for the first time since the comedian's death this morning.

Zelda was the focus of her father's final Instagram photo two weeks ago, in which he wished her a happy 25th birthday.

Robin Williams' message was accompanied by an old black and white photo of himself with his then-infant daughter.

Zelda's message to her father was accompanied by a quote from French novella The Little Prince, by Antoine De-Saint Exupery.

The chosen quote reflected their close relationship, as well as the laughter Williams brought to the lives of audiences across generations and across countries.

Williams, a beloved comedian and actor, was found dead at his US home of an apparent suicide.

He had battled addiction and depression for years, including an ongoing struggle against alcoholism.

Zelda, the daughter of Williams and his former wife Marsha Garces, was named for the one of the comedian's favourite video-game characters.

She was a regular sight on the red carpet at her father's film premieres, and appeared with him in the 2004 film House of D.

US website HollywoodLife.com quoted a source close to Zelda saying the young actress was "inconsolable" on hearing about her father's death.

Williams has fathered two other children, eldest son Zachary with his first wife Valerie Velardi, and Cody Alan, also with Garces.