The veteran striker, who is the Baggies' top-scorer with 24 goals this season, was also linked with free transfer switches to Wigan Athletic and Derby County.
"I want to stress to the supporters that this is nonsense, I have not rejected a new contract and I haven't a clue who the so-called source of the story is supposed to be," he said.
"We've got two massive games coming up and we're all going to sit down after our season has finished and try to come to an agreement over the future."