Charles Leclerc has admitted Ferrari are unlikely to catch Mercedes and make a fight of the championship before the end of the season.
Mercedes have won all eight races this season and Ferrari have so far failed in their attempts to close the performance gap between the two cars.
"We will believe it until the end, of course," said Ferrari driver Leclerc. "We are all aware the gap is quite big.
"It'll be difficult to catch up, but we won't give up until it's not possible."
But his team-mate Sebastian Vettel was more optimistic.
The four-time champion said: "I'm confident we have what it takes. We haven't proved it yet and hopefully we will be able to turn it around sooner rather than later, not only for us, but also for you.
"We are flat out. We are trying to improve the car."
Ferrari's car is on average nearly 0.4 seconds a lap slower than the Mercedes in qualifying and the team have only had two clear-cut chances to win races this season.
In Bahrain, Leclerc was on course for a dominant victory before his engine hit trouble in the closing laps and he dropped to third.
In Canada, Vettel was leading Mercedes' Lewis Hamilton only to make a mistake, run off track and then receive a five-second penalty for dangerous driving against Hamilton when he rejoined.
Apart from Azerbaijan, where Leclerc looked a strong favourite for pole before crashing in qualifying, Ferrari have lagged behind Mercedes at every race.
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Leclerc said he did not expect to be able to challenge Hamilton and his team-mate Valtteri Bottas this weekend in Austria, even though the track layout rewards engine power, the only area where Ferrari lead the field.
Asked if Ferrari could take on Mercedes at the Red Bull Ring, Leclerc said: "Oof. I think at the moment it is quite difficult. They seem very, very quick.
"To be honest it is quite difficult to be at their level. If they don't run into issues, it is troubling for us to challenge them."
Despite Leclerc's pessimism, Hamilton does not believe Mercedes face a straightforward weekend.
"Last year, we had a double DNF so for sure you imagine all the engineers are on the edge of their seats and a bit nervous because it's always hot here. It's 700m altitude. There are only 10 corners, but the cars are always on the limit in terms of cooling," he said.
"The cars are heavier this year so the brakes are going to be even worse and they end up having to open up the car to create cooling and that is always worse for the car aerodynamically, so you lose performance.
"Ferrari's car works differently on different tracks so it is going to be interesting to see where we stand with them."
Ferrari took some new parts to the French Grand Prix last weekend in an attempt to close the gap to Mercedes but they had mixed results.
A new front and rear wing and brake ducts were left on the car, but a new floor was taken off.
Team boss Mattia Binotto said: "We are happy to be getting back on track so quickly, because it's the best way to put ourselves to the test again to try and understand the elements that did not go according to plan in France. We have various test items to evaluate."
In other developments, teams are meeting with governing body the FIA and tyre supplier Pirelli on Friday morning to discuss a proposal led by Red Bull to revert to last year's tyre design.
Thinner-gauge tyres were introduced for 2019 in an attempt to reduce their propensity for overheating, but Red Bull and others believe that this has favoured Mercedes, who in the past have been one of the teams that most struggled with keeping tyre temperatures under control.
By contrast, many teams this season have struggled to get the new tyres up to the right temperature window for them to work properly.
Seven of the 10 teams would need to agree for a change to come in mid-season - most likely after the summer break, which comes in August after the next four races in Austria, Britain, Germany and Hungary.
Vettel said: "As it is now, it is fairly set in terms of order. Mercedes are doing a very good job. It would be an element to try to mix things up.
"We struggled a lot more to get the tyres into the window for qualifying and race this year. For us, it is pretty clear, but everyone has their own opinion."
Hamilton said the 2018 tyres were "worse" than the current ones, adding: "Last year, you had to manage the tyres to a temperature so you had more lift and coasting, more blistering. It was a lot worse. You couldn't do what I was able to do in the last race, or even in Montreal, where I was able to push behind Seb for all those laps.
"That is an example of different teams pushing for their own personal goals rather than the sport."
|Austrian Grand Prix coverage details|
|Date||Session||Time||Radio coverage||Online text commentary|
|Friday, 28 June||First practice||10:00-11:30 BST||BBC Sport online||From 09:30 BST|
|Second practice||14:00-15:30||BBC Sport online||From 13:30|
|Saturday, 29 June||Final practice||11:00-12:00||BBC Sport online||From 10:30|
|Qualifying||14:00-15:00||BBC Sport online||From 13:00|
|Sunday, 30 June||Race||14:00-16:00||BBC Radio 5 Live||From 12:30|
|Monday, 1 July||Review||04:30-05:00||BBC Radio 5 Live|
|Chequered Flag podcast: Austrian Grand Prix review - download here once the race has finished|