The all-female W Series will race on the Formula 1 support package at the United States and Mexican Grands Prix in 2020, expanding its second-season calendar to eight rounds.
Following a successful inaugural season in 2019, which comprised six rounds supporting DTM events, the W Series has been in discussion with F1 for some months about the possibility of joining the support bill at several races.
The back-to-back US and Mexico races, at which F1's regular support series Formula 2 and Formula 3 will not appear, will count towards the championship and represent what W Series described as "an exciting double-header championship decider" in October.
F1's managing director for motorsport Ross Brawn said: "We are delighted to welcome W Series to two such spectacular events of the 2020 FIA Formula 1 world championship such as those in Austin and Mexico City.
"In just one year, W Series has contributed significantly to increasing interest in the topic of diversity and inclusion in motorsport.
"We are convinced that our sport must offer equal opportunities for men and women to compete together - it is no coincidence that improving the diversity of the F1 grid by supporting and promoting driver talent from under-represented backgrounds is one of our strategic objectives.
"The ability for the great crowds who traditionally attend the Austin and Mexico City Grands Prix to see these talented female drivers up close will definitely further raise the awareness of the importance of inclusion and diversity in motorsport."
W Series CEO Catherine Bond Muir added: "Interest in and enthusiasm for W Series was enormous in our first season, 2019, among media and fans alike, and the addition of two all-new W Series races on the Formula 1 platform will inevitably increase that enthusiasm and interest.
"Commercially, too, following the successful recent announcement of W Series' new multi-year sponsor-partnership with ROKiT Phones, the fact that W Series will be even bigger and even better in 2020 than it was in 2019 will make the return on investment for our future sponsor-partners better and bigger, too.
"A lot of work has gone into stitching the W Series/Formula 1 deal together, but above all I want to thank W Series' drivers, the brave and talented young women who captured the imagination of the sporting world last summer.
"Mark my words: they'll do so again this year, from May to October, all over the world."
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W Series previously revealed a provisional six-round calendar again following the DTM circus, while declaring more events were due to be added in due course.
The 'double-header' will take place seven weeks after the final round of W Series' European schedule, which will be held at Assen on September 5.
The eight-round campaign begins at Igora Drive in Russia on May 30.
In the second season, W Series drivers will be eligible to earn superlicence points for the first time.
The inaugural W Series campaign was won by Williams development driver Jamie Chadwick, who will defend her crown in 2020.