Honda has said cost remains the biggest factor in deciding whether or not it will continue to take part in Formula 1 as an engine supplier after the 2020 season.
The Japanese manufacturer has an agreement with Red Bull for 2020, but after next season its future remains unclear, although a decision is expected imminently with the FIA's deadline for confirmation approaching.
Honda returned to F1 with McLaren in 2015 but endured a tough time which eventually resulted in the two parties splitting. Honda came close to dropping out but a deal was struck with Toro Rosso for 2018 and sister team Red Bull followed in 2019 as Honda's performance edged closer to its rivals.
It claimed its maiden podium since returning at the very first race in Australia, followed by nine further podiums in 2019 – two with Toro Rosso – of which three have been race wins thanks to Red Bull's Max Verstappen.
But Honda's F1 managing director Masashi Yamamoto says race wins aren't enough to secure the manufacturer's future in the sport.
"We have started to calculate how much it will cost with the future regulations," Yamamoto told Autosport.
"We have noticed that it's very tough for all the car manufacturers at the moment, because of the environment change for electrification. So, we are summing up the development cost and having discussions internally."
Asked what was the biggest hurdle to overcome, he added: "Cost is the biggest issue. It's positive to have good results, but more important thing is a balance with the cost. We have to put lots of budget to accelerate our development to catch up the top runners.
"Now we are planning how to maintain current condition and reducing the cost at the same time."
