The holders, whose team boasts a world or Olympic medallist in six of the eight weight classes, have been drawn in Group B with Azerbaijan, India and hosts the United States.

India didn’t qualify as one of the top eight nations at last year’s World Championships but were invited with Bulgaria unable to attend.

Iran are led by 57 kilogram star Hassan Rahimi, a four-time world medallist and 2013 world champion, and London 2012 Olympic bronze medallist Komeil Ghasemi at 125kg.

Rahimi is ranked number two in the world, while Ghasemi is number six.

Also competing for Iran are two-time world medallists Masoud Esmaeilpoorjouybari and Sayed Ahmad Mohammadi at 61kg and 65kg respectively.

They are joined by Hassan Yazdani Charati, at 74kg, and Alireza Karimimachiani, at 86kg.

Russia, winner of eight of the past nine Freestyle World Championships, will be looking to break Iran’s stranglehold on the event and feature in Group A alongside Georgia, Turkey and Mongolia.

Their team is led by a trio of world champions - Soslan Ramonov at 65kg, Khetik Tsabolov at 74kg and Abdusalam Gadisov at 97kg - with all three ranked in the top four in the world in their respective weight classes.

Also competing for Russia is 2013 world bronze medallist Magomed Kurbanaliev, who is currently fifth in the 65kg world rankings.

European champions Shamil Kudiamagomedov and Gadzhimurad Rashidov are expected to be key contributors for Russia as well. 

Kudiamagomedov is ranked number two in the 86kg global standings, while Rashidov sits at number nine in the 57kg equivalent.

The results from the group stage, which begins tomorrow, will determine the placement matches on Sunday (June 12).

Iran secured their fourth consecutive title last year by beating the US in the final at the same venue.