Max Verstappen believes that Red Bull need to "step it up" if they are to remain in the title battle right until the end of the season.
The Dutchman retook the lead in the World Championship standings at the Turkish Grand Prix after finishing in second, whilst title rival Lewis Hamilton ended the day in fifth.
However, Valtteri Bottas' dominant victory showed the pace of the Mercedes, and Verstappen thinks this highlights that Red Bull still have work to do.
"Of course, overall, I think we have been at tracks that naturally were a bit better for Mercedes, but then this track was a bit unknown, and clearly they were ahead of us," Verstappen told Sky Sports.
"I do think we need to step it up a bit to be in the fight until the end of the season."
With six races remaining, Verstappen only has a six-point advantage over Hamilton, whilst Mercedes still sit ahead of Red Bull in the Constructors' Championship with a 36-point lead.
Despite 2021 proving to be a strong season for Verstappen and Red Bull, the 24-year-old believes that the Silver Arrows have had the edge when it comes to straight-line speed for "most of the season".
"Of course, they've sorted their car out, so it's a bit more obvious that top speed they have," Verstappen explained.
"It's what we have to live with, it's not going to magically disappear, but of course, we'll try to minimise the damage on the straights."
Verstappen was nonetheless happy to secure a solid result for the team in Istanbul Park, particularly given that teammate Sergio Perez claimed his first podium in several races by finishing in third.
"Overall, on a weekend where we were off the pace compared to them [Mercedes], to come away with second here, and third with Checo, as a team [it's] a great result."
F1 Podcast: Do Mercedes need to assert more authority over Hamilton?
It's time for the latest episode of the RacingNews365 podcast, with F1 journalists Dieter Rencken, Thomas Maher and Mike Seymour discussing Lewis Hamilton's strategy drama and much, much more from the Turkish Grand Prix.