A report is circulating in Singapore claiming that Toro Rosso and Honda will embark on a three-year partnership at the start of next year.
The Japanese manufacturer initially sought to contract with a second team for 2018, but a tentative agreement with Sauber was ultimately scrapped, bringing Toro Rosso into the frame.
Following the formal dissolution of the McLaren-Honda partnership, the manufacture has agreed to a three-year deal with the Faenza-based outfit, according to Motorsport.com.
The three-year period, similar to the McLaren-Renault deal, will take all parties to the end of 2020 when Formula 1's current engine regulation platform expires.
A Toro Rosso-Honda partnership is also considered to be a prelude, or proving period, before Red Bull Racing also switches to Japanese power.
However, the Milton Keynes-based outfit has apparently been informed by current engine partner Renault that it will no longer supply its engine to Red Bull after the end of the 2018 season.
The decision would appear to leave the team with no other choice but to contract with Honda for 2019, while hoping that the manufacturer can solve its persistent performance and reliability issues over the next 12 months.