Leonard Nimoy
Twitter is flooded with tributes to the actor who played Spock in Star Trek.AFP / Getty Images

President Barack Obama has paid tribute to Leonard Nimoy who died today, aged 83.

Releasing an official statement on the passing of the much-loved actor, the US President said he "loved Spock."

"Long before being nerdy was cool, there was Leonard Nimoy," said Obama. "Leonard was a lifelong lover of the arts and humanities, a supporter of the sciences, generous with his talent and his time. And of course, Leonard was Spock. Cool, logical, big-eared and level-headed, the center of Star Trek's optimistic, inclusive vision of humanity's future. I loved Spock."

Recalling an occasion when he met the actor in person he said: "In 2007, I had the chance to meet Leonard in person. It was only logical to greet him with the Vulcan salute, the universal sign for "Live long and prosper." And after 83 years on this planet – and on his visits to many others – it's clear Leonard Nimoy did just that. Michelle and I join his family, friends, and countless fans who miss him so dearly today."

William Shatner, who played Captain Kirk in the hit US series Star Trek, paid an emotional tribute to his co-star and close friend. He said: "'I loved him like a brother. We will all miss his humour, his talent, and his capacity to love.'"

The relationship between the Captain of the Enterprise and his second-in-command is a central feature of the Star Trek series, and just as Kirk and Spock shared a loyal bond, Shatner and Nimoy forged a close real-life friendship. Nimoy was even best man at Shatner's wedding in 2000.

Star Trek actor George Takei, who played Sulu in the original series, paid an emotional tribute to his friend saying he would miss him in "many, many ways".

"Today, the world lost a great man, and I lost a great friend. We return you now to the stars, Leonard. You taught us to "Live Long And Prosper," and you indeed did, friend. I shall miss you in so many, many ways."

Sci-fi stars who have followed in Nimoy's footsteps turned to Twitter to pay tribute to the pioneering actor.

Actor Zachary Quinto, who took over as Mr. Spock in the reboot and its sequel, posted a photo of the actor on Instagram with the heartfelt message: "My heart is broken. i love you profoundly my dear friend. and i will miss you everyday. may flights of angels sing thee to thy rest."

Will Wheaton from Star Trek: The Next Generation wrote: "We stood on your shoulders, and wouldn't have had a galaxy to explore if you hadn't been there, first. Thank you, Leonard, Rest in peace."

David Baddiel wrote poignantly: "Leonard Nimoy dying seems somehow...illogical."

Bollywood star Shah Rukh Khan recalled the iconic character posting an image of is own Vulcan salute as he paid his respects. Nimoy, who was part of the franchise for almost 60 years was first cast in the role of Spock in 1966. He played the Vulcan one last time in the reboot of Star Trek: Into Darkness in 2013. It was Nimoy's final film role.

The actor who suffered from COPD - chronic obstructive pulmonary disease - frequnetly warned his fans of the perils of smoking which is a key cause in the disease. He was rushed to the UCLA Medical Centre after a 911 call on February 19.

The star sent a final tweet on Monday which read: "A life is like a garden. Perfect moments can be had, but not preserved, except in memory. LLAP" The 83-year-old passed away at his Bel Air, Los Angeles home on Friday 27 February , following his long battle with lung disease.

Danni Schwartz, Nimoy's granddaughter, also paid a perosnal tribute to her grandfather saying: "Hi all, as you all know, my Grandpa passed away this morning at 8:40 from end-stage chronic obstructive pulmonary disease. He was an extraordinary man, husband, grandfather, brother, actor, author-the list goes on- and friend. Thank you for the warm condolences. May you all LLAP."

She is selling 'Live Long and Prosper' t-shirts online to raise money for charities researching COPD.

Nimoy is survived by his second wife, two children, Adam and Julie Nimoy, six grandchildren and a great-grandchild.