The struggling Caterham and Marussia Formula One teams will both miss next week's U.S. Grand Prix in Austin, Texas, the sport's commercial supremo Bernie Ecclestone told Reuters on Saturday.
"Neither of those two teams are going to go to America," said the 83-year-old.
Caterham went into administration on Friday while Russian-registered Marussia are also struggling financially and are still reeling from French driver Jules Bianchi's serious accident in Japan three weeks ago.
The air transport for all the teams' cars and freight is organised by Ecclestone's Formula One Management and they were due to be flown out on Saturday.
By missing the race in Austin, the two teams will also be absent from Brazil since the races are back to back with the cars going direct from the United States to Brazil before returning to Europe.
The final race of the season is in Abu Dhabi on November 23, when double points are to be awarded for the first time.
Neither the administrator of Caterham nor representatives of Marussia, who are currently ninth in the championship thanks to Bianchi's ninth place in Monaco in May, were immediately contactable.
However, Ecclestone said on Friday that Caterham had been given a dispensation to miss the next two races while they sought a buyer.
Marussia's absence, apart from giving 10th placed Sauber more of chance to overtake them in the championship, will leave the grid in Austin with only nine teams and 18 cars.
It also wrecks the hopes of American Alexander Rossi, the Marussia reserve, making a home appearance at Austin.
Ferrari-powered Marussia ran only one car in Sochi, Russia, two weeks ago, as a mark of respect for Bianchi who remains in critical condition in hospital in Japan after his horrific crash at Suzuka.
There has been no medical update on Bianchi's condition since Sochi.
Caterham's two drivers are Japan's Kamui Kobayashi and Sweden's Marcus Ericsson.
