The former champions made a step with its Barcelona upgrade, but the RB13 is still clearly behind Mercedes and Ferrari.
“We have to catch up and especially the improvements from our partner Renault are delayed,” Mateschitz, the low-profile founder of the energy drink company, told Salzburger Nachrichten newspaper.
“So we have to be patient until we get closer to Mercedes and Ferrari,” he said.
Amid Red Bull’s struggle, team drivers Daniel Ricciardo and Max Verstappen have each been linked with a potential move to Ferrari for 2018.
But Mateschitz said the pair’s respective contracts are “of course” watertight.
“And where would they go?” said the Austrian billionaire. “There will not be places free at either Mercedes or Ferrari.”
Finally, 72-year-old Mateschitz commented on the new era in F1 overseen by Liberty Media, as a series of fan-friendly initiatives made their bow in Barcelona at the weekend.
“It is clear that the new owners are very keen to innovate,” he said, “and above all to do something more for the audience.
“We also have to give them time, but they do the right things so far,” said Mateschitz.
Asked what his wishes are for the future direction of the regulations, he answered: “We would want an independent engine manufacturer so there is no longer this dependence on manufacturers.
“But this is a long-term wish for the regulations after 2020,” added Mateschitz.