World championship leader Charles Leclerc praised the enthusiasm of Ferrari's many American fans on Saturday, but warned of a tense battle ahead after leading the Italian team to a front-row lockout at the inaugural Miami Grand Prix.

The 24-year-old Monegasque claimed pole position ahead of his Ferrari teammate Carlos Sainz after Max Verstappen made a rare error and slipped to third on the grid for Red Bull at a packed Miami International Autodrome.

"The fans are crazy," said a beaming Leclerc. "But it's incredible to be here in the United States and to see how much the sport has grown over the last few years."

"The last race weekend wasn't great for me. I made a mistake in that race. But today it went well. Red Bull are extremely quick in the straight lines, but we are quick in the corners and it will be a tight challenge tomorrow. We feel very motivated as there are so many Ferrari fans here."

Leclerc clocked a fastest lap in one minute and 28.796 seconds to outpace teammate Sainz by two-tenths.

Verstappen was third after making a slight mistake on his final flying lap. His Red Bull teammate Sergio Perez was fourth with Valtteri Bottas fifth for Alfa Romeo and seven-time champion Lewis Hamilton sixth for Mercedes.

"Overall, I'm pretty pleased with qualifying," the Dutch driver said.

"I literally did four or five laps yesterday. The whole of today I was trying to learn the track and trying to find a decent balance in the car and actually, to be that competitive in qualifying, it was a bit of a surprise because this is not an easy track to learn," he added.

Sainz, who recovered well after a crash in practice on Friday, said it had not been easy to regain his confidence and push hard on such a punishing circuit.

"Building up a bit from a pretty heavy crash," he said. "It wasn't easy at all to get the confidence back in such a difficult circuit like this new one."

It was Leclerc's third pole this year and the 12th of his career. For Sainz, it was the second time he had secured a front-row start. It was Ferrari's first front-row lockout since the 2019 Mexican Grand Prix.

Hamilton was relieved with a place on the third row after Mercedes suffered the ignominy of failing to qualify either of their cars in the top 10 at the Emilia Romagna Grand Prix.

"This is much better than last week for me," he said. "So, I'll take it. The car is a little better, but we have to keep working and keep our heads down."

His teammate George Russell qualified 12th.

"It's confusing," he said. "My lap was slower today than I was in second practice yesterday. There was potential in there, but it's feeling too inconsistent."