Chicago Marathon winner Daniel Romanchuk ©Getty Images

United States wheelchair athletes Daniel Romanchuk, Tatyana McFadden and Susannah Scaroni have qualified for next year's Paralympic Games in Tokyo following their performances at the Chicago Marathon.

Romanchuk, who competed at Rio 2016, became the first American man to win a World Marathon Majors title after victories in four races during the series, which included becoming the first American man to win the New York City and Boston marathons.

"This has been an incredible morning with this being the Tokyo 2020 qualifier," Romanchuk, who successfully defended his men's title in Chicago, finishing more than three minutes clear of Britain’s second-placed David Weir, said following the race. 

"I'm having a difficult time finding the words to describe this feeling.

"It's an honour to be named to the team and represent the US at the Tokyo Games.

Second place in the weekend's Chicago Marathon earned United States wheelchair athlete Tatyana McFadden a sixth Paralympic appearance at Tokyo 2020 ©Getty Images
Second place in the weekend's Chicago Marathon earned United States wheelchair athlete Tatyana McFadden a sixth Paralympic appearance at Tokyo 2020 ©Getty Images

The 17-time Paralympic medallist McFadden secured her spot in her sixth Paralympic Games after placing second behind Switzerland's Manuela Schar in Chicago, where she was the first US female finisher.

Earlier this season, McFadden finished second in the World Marathon Majors.

Scaroni, a two-time Paralympian, placed fourth in Chicago and fourth in the overall World Marathon Majors rankings.

Additional athletes will qualify for Tokyo 2020 when the US Paralympic Team Trials are due to take place from June 25 to 28 next year in Minneapolis.