The Holland international joined the team in 2023 after transferring from Ajax and is currently under a contract until 2028.
Arsenal's decision to engage in contract talks with Timber comes as a result of his consistent performance since recovering from a knee injury two years ago.
During his recovery, Timber made 51 appearances, solidifying his position as a first-choice player under manager Mikel Arteta.
Arsenal's recent move to upgrade and extend Timber's contract follows the team's decision to secure a new deal for William Saliba just days prior.