Hamilton's £40million-a-season deal expires at the end of the year and the British driver, who will this term bid for a record-equalling seventh world championship, has been linked with a move to Ferrari.
Reports in Italy claim talks over a contract extension between Hamilton and Mercedes boss Toto Wolff have stalled.
But in a post to Instagram which he later deleted, Hamilton wrote: "Toto and I have not even spoken about contract yet. Nothing is being negotiated currently."
Both Ferrari and Red Bull have moved to tie Charles Leclerc and Max Verstappen respectively to long-term deals during Formula One's off-season.
But Hamilton, who has spent much of the winter break in America, is unlikely to rush into a decision on his future.
Ferrari confirmed their interest in Hamilton last year, and are set to need a replacement for Sebastian Vettel in 2021 if the four-time world champion's deal is not renewed.
Hamilton, 35, can match Michael Schumacher's record of seven titles if he wins the championship again this year.
The Englishman will get his first drive of the new Mercedes he hopes will fire him to further glory in the team's behind-closed-doors launch at Silverstone on February 14.
The first pre-season test gets under way in Barcelona five days later before Hamilton opens his title defence in Melbourne on March 15.