Haas's new Formula One technical partnership with Toyota is aimed at enhancing long-standing arrangements with Ferrari rather than replacing them, team boss Ayao Komatsu said on Friday.
The team uses Ferrari engines and gearboxes, as well as a wind tunnel and simulator at Maranello where Haas maintain a design office.
Ferrari's British reserve driver Oliver Bearman, who has come through the Italian team's academy, will be racing for Haas next season.
"Our partnership with Toyota is not to replace the Ferrari partnership," Komatsu told reporters after the Toyota announcement at Japan's Fuji Speedway.
"The Ferrari-Haas partnership is the foundation, and it's always going to be the foundation.
"This [Toyota] partnership is not to take away from it, but to enhance that fundamental partnership with Ferrari. What we have with Ferrari, what we get from Ferrari, is amazing."
Komatsu, a Japanese engineer who replaced Guenther Steiner as team principal in January, said Haas had been completely transparent with Ferrari management from the early stages of discussion.
He said there was a clear understanding of the need to protect intellectual property and Ferrari had been given assurances.
Toyota will provide Haas with simulator access while young Japanese drivers will get track time as part of a TPC (testing of previous cars) programme.
A Toyota-backed driver could ultimately get a reserve role, although any decision would be based on talent rather than funding.
"Ferrari sent certain requirements where I had to guarantee them we continue with this and this and this. That's what we were going to do anyway, so it was pretty straightforward really and very collaborative from all sides," Komatsu said.
Haas will continue to use Ferrari's wind tunnel while the powertrain deal runs to the end of 2028.
The relationship with Italy-based chassis designer Dallara will also continue.
"We will keep the Maranello design office... our aerodynamicists will continue to be based there," Komatsu added, who said Toyota would provide Haas with more resource and hardware.
"We will start designing some other carbon composite parts by ourselves and then also start doing some testing and simulator work," he said.
"They [Toyota] are looking for the latest F1 know-how and skill-set which we have but we don't have their facilities, we don't have the number of people and resource. So that's how we are tapping into each other's expertise."
"So it's really a perfect combination to have a mutual benefit."