US President Barack Obama called Robin Williams "one of a kind" who shared his talent "freely and generously with those who needed it most".
Williams was pronounced dead at his home in California on Monday and officials said it appeared to be a suicide.
Obama said in a statement issued on Monday night that Williams "arrived in our lives as an alien - but he ended up touching every element of the human spirit", referring to Williams' late 1970s role in the TV show Mork and Mindy. The president was on vacation on Martha's Vineyard, Massachusetts.
The president said the actor was generous with his comic talents for those who needed it, including troops abroad.
The statement said: "The Obama family offers our condolences to Robin's family, his friends, and everyone who found their voice and their verse thanks to Robin Williams."
(China Daily 08/13/2014 page10)