The 2016 gold medallists and reigning world champions had a slight lead going into the final leg and anchor Lynna Irby charged through the last lap to win the heat by more than a second, with Jamaica and Britain also advancing.

Poland won their heat in 3:23.10s, in another impressive performance after their upset win in the inaugural mixed event last week, as Cuba finished second and Belgium third in a national record 3:24.08s.

Six-time Olympic gold medallist Allyson Felix is expected to join the US team for Saturday’s final, in her fifth and final Games.