The striker, who joined the Blues from Manchester City in 2009, expressed his delight at joining the Merseyside club.
“I am humbled and happy to be here,” he said. “Brendan Rodgers said he sees me here for a long time – and I also see myself here for a long time. I’ve not signed here to play for a couple of years and then move on.
“I’ve signed to be here for as long as possible. It’s a humongous club – for me, one of the biggest in the world – and to have the fans and world-class players we have here is amazing.”