Out of contract at the end of this season, Hamilton and Mercedes elected to postpone renewal talks until the star driver had wrapped up his seventh Formula 1 title.
Hamilton recently said he'd like to have a new deal sorted before Christmas, a target that looks set to be comfortably met based on a tweet from the Mercedes team.
Under the caption #Announce the squad tweeted a quote from Hamilton expressing a desire to sign on for 2021.
"I plan to be here next year. I want to be here next year," the quote read.
"I think we as a team have more to do together and more to achieve, both in the sport but even more outside it."
Confirmation of a new Hamilton deal will formally lock in the Mercedes line-up for the 2021 season, with Valtteri Bottas already signed.
Hamilton was, however, listed as a Mercedes driver on the initial FIA entry list that was unveiled last week.
Mercedes and Red Bull are the last two teams to make their 2021 line-ups official, although the latter is expected to announce Sergio Perez alongside Max Verstappen as soon as today (Friday).
