Turkey will replace Canada on this year's Formula One calendar after the June 13 race in Montreal was cancelled for the second year in a row due to the coronavirus pandemic.
F1 said it had extended Montreal's contract by two years to take into account the cancellations, securing the race until 2031.
The race had been scheduled for the Circuit Gilles Villeneuve at the weekend after the Azerbaijan Grand Prix and Turkey's Istanbul circuit will be logistically convenient for air freight coming from Baku.
The Turkish race returned last year for the first time since 2011 and also at short notice to bolster a calendar ravaged by the pandemic.
Canada is experiencing a rise in cases, with Ontario – neighbouring province to Quebec – particularly badly affected.
"Due to the ongoing international travel restrictions in place in Canada it became impossible for Formula One to enter the country without a mandatory 14-day quarantine," the governing body said in a statement.
The sport has operated in a bubble, with teams and staff regularly tested and many vaccinated while races have been held behind closed doors.
2020 Turkish GP: @LewisHamilton celebrates winning his seventh world title 🏆
— Formula 1 (@F1) April 28, 2021
2021 Turkish GP: ❓ 👀 ❔#TurkishGP 🇹🇷 #F1 pic.twitter.com/hOd2FTAfMD
F1 said that more than 78,000 Covid-19 tests conducted last season produced only 78 positive results. There have been more than 12,000 tests this season with 14 positives.
"I want to thank the promoter and authorities in Canada for all of their efforts in recent weeks but the travel situation made our plans impossible," said chief executive Stefano Domenicali.
"I equally want to thank the promoter and authorities in Turkey for their ongoing willingness to host a Formula One race that shows the huge interest in our sport and the hope from many locations to have a Grand Prix."
Last year's wet and slippery grand prix at Istanbul Park was held in November and produced one of the highlights of the season, with Mercedes' Lewis Hamilton clinching a record-equalling seventh world title.
F1 said it would work with the Canadian promoter to refund or transfer tickets.
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