Leclerc is into the pitspublished at 20:52 British Summer Time
20:52 BST
Lap 27/56
Race leader Charles Leclerc is called in next by Ferrari. Medium tyres dumped, hard tyres bolted on, and the Monegasque driver rejoins in third place. Lando Norris now takes control with McLaren team-mate Oscar Piastri in second place.
Pierre Gasly is running in 15th place but the Frenchman is far from happy in that orange Alpine, flagging struggles on his fresh hard tyres. There is a little train now of Gasly, Alex Albon and Lance Stroll.
Verstappen pitspublished at 20:49 British Summer Time
20:49 BST
Lap 26/56
Here comes the Red Bull. Max Verstappen is changed quickly on to the hard tyres and as he heads back out at COTA, he slips in behind the Ferrari of Carlos Sainz, who is on the same rubber, but four laps older.
Marc Priestley Former F1 mechanic on BBC Radio 5 Live
Leclerc is obviously a bit nervous but from a Ferrari pit-wall point of view it's always the hardest position on the race track to make that call from. You're leading the race, not really under too much pressure, there's a free pit-stop in terms of nobody is going to undercut him and he's not been pushed too hard.
He also doesn't want to leave it too long that he comes under pressure from his team-mate Carlos Sainz and Max Verstappen.
The questions are coming thick and fast for Charles Leclerc, which is not what you want when you're leading a 56-lap race. Max Verstappen is also feeling the heat, flagging to his pit wall that his left-side tyres are looking a bit dodgy.
The advantage Charles Leclerc possesses over the Red Bull of Max Verstappen is now over 10 seconds, but the Monegasque driver does not want to be at the mercy of other quicker drivers if he's left out too long.
Race control had a little look at an incident between Kevin Magnussen and the Williams of Alex Albon. Did the Haas force Albon off the road? The verdict is no, your honour.
You know Charles Leclerc's done 22 laps on a set of medium tyres and Sainz is about to come in, so that leaves him with 34 laps to do on a set of hards.
Franco Colapinto is taking part in his first United States Grand Prix and in his bid to score some more points, his next car on the to-do list to pass is the godfather of the grid, Fernando Alonso. Job done. Argentine Colapinto is up to 10th.
Sainz comes in to pitpublished at 20:43 British Summer Time
20:43 BST
Lap 22/56
Box this lap, Carlos. Ferrari make the call to the Sainz to dump his starting mediums for a set of the hard rubber. The Spaniard heads back out in fifth place behind the McLaren of Oscar Piastri.
Will Carlos Sainz try his luck with an undercut on second-placed Max Verstappen? We'll wait and see. Over at McLaren, both drivers are feeling happy with how the medium tyres have performed so far.
'Good pace' from Leclercpublished at 20:41 British Summer Time
20:41 BST
Marc Priestley Former F1 mechanic on BBC Radio 5 Live
Leclerc is doing a really nice job of looking after the tyres while maintaining a really good pace, he still keeps going quicker and quicker at times, some really fast laps.
The first stints are coming to an end and all eyes are on who is going to blink first. Charles Leclerc has an eight-second gap to Max Verstappen and has just banked another fastest lap in the Ferrari.
Marc Priestley Former F1 mechanic on BBC Radio 5 Live
On strategy, everyone is looking at Liam Lawson, the problem the front runners have got is Liam on that harder tyre, you are not going to see a deterioration rate until beyond the point where the medium runners really need to commit to their strategy because their tyres are going to go on first.
At some point very soon we are going to see somebody think about pulling the trigger and getting into the pit-lane.
Yuki Tsunoda hears the bell to come in to pits for hard tyres. The RB man is in and out and rejoins the action in 17th place. Nico Hulkenberg in up to seventh, Liam Lawson is eighth and George Russell is now ninth.