Red Bull has escalated its psychological tactics as the championship battle with McLaren reaches a critical stage.

Dr. Helmut Marko wasted no time heading into the US Grand Prix in casting doubts about Lando Norris' "mental" resilience. This comes after and amid a tense back-and-forth between Red Bull and McLaren over technical details like flexible wings and adjustable 'T-trays.'

Marko, 81, speaking to the Osterreich newspaper, also expressed his view that McLaren may have blown Norris' chances of catching up with Max Verstappen, who holds a 52-point lead, as the final six races of 2024 approach.

"McLaren is consistently fast," Marko said. "But they waited too long to make a clear commitment to Norris."

Max Verstappen added fuel to the fire by offering Oscar Piastri some cheeky advice, suggesting that he should think twice before accepting any team orders.

"For me, he (Piastri) is absolutely not a number 2 driver and, if I were him, I would never accept it," Verstappen commented in Austin.

"He is a great driver who doesn't deserve to have to give up victories and positions to play a second-rate role just because he is asked to."

Gerhard Berger, a long-time supporter of the Red Bull camp, also weighed in during an interview with Kronen Zeitung, praising McLaren for having "two number 1s" in its lineup but pointing out that this could backfire.

"Because of that, they've been taking points away from each other in the championship. If they want to prevent Verstappen from defending his title, they have to put everything on Norris now.

"I think it will be very close in the end, but I think Max will be able to bring it across the finish line."

Meanwhile, Marko noted that Red Bull's engineers are feeling "optimistic" about the new updates being introduced in Austin.

Verstappen, however, warned that time has been tight to implement the changes, despite the three weekend break since Singapore.

"I haven't tried them out in the simulator," he said. "So it's difficult to say how it will feel on the track. And just 60 minutes of practice here is tricky.

"But I'm not thinking too much about it all yet in terms of successfully defending or losing the title. If the improvements work, I'll be in good spirits, and if they don't, I think it will be very difficult for us.

"For me, it's 50-50. And I think every race from now on is decisive. Of course I want to win it in the end, but we need to be competitive enough for that. It's that simple.

"Of course I want to win, but if we don't make it, it's not a great tragedy for me."