Honda is no longer "far away" from its more powerful engine rivals in F1.

That is the view of Franz Tost, the Toro Rosso team boss. The Red Bull-owned team used works Honda power in 2018, after the three failed years of the McLaren-Honda collaboration.

And now, Red Bull's senior team will also use Honda power from 2019.

"Honda did a fantastic job throughout the year. Performance improved a lot, and also the reliability," said Tost.

Honda's F1 boss Masashi Yamamoto confirmed Tost's summary.

"Initially we were not as quick in the development as we wanted to be," he said, "but at the end everything was much better.

"Regarding 2019, we are very pleased to also work with a top team. Obviously there is pressure, but we will turn it into good energy to bring us fantastic results," added Yamamoto.

Tost says Honda improved throughout 2018 and then carried that momentum into the winter period.

"There are on the right way and will improve during the winter months," said the Austrian.

He denied that one big worry for 2019 will be reliability, after Toro Rosso's drivers had to take engine change penalties last year.

"With regards to reliability, Honda exceeded expectations," said Tost. "We thought we would have many more problems but to be honest we didn't have any major issues.

"Also regarding performance, with the new specification we were not far away from the top teams."

As for the prospect of engine penalties in 2019, however, Tost admitted: "I don't know yet how many power units we will use in the end.

"For me, three power units is wrong from the regulation side. We should have the possibility to get more but I hope this will change from 2021 onwards."