[2] He also set a new IAAF Diamond League record at the IAAF Diamond League in August 2016 in the men's 1000 meters [3] Souleiman's first international appearances came in 2009, when he placed tenth in the 1500 m at the Jeux de la Francophonie and ran in the heats of the 3000 m at the World Youth Championships.

[4] In 2011, Souleiman won the title of 1500 m of the 2011 Pan Arab Games in Doha, in a time of 3:34.32, to win his country's first medal in this competition.

[6] The following season saw him appear on the global scene, as he reached fifth in the final at the 2012 IAAF World Indoor Championships.

Souleiman won the bronze medal at the 2013 World Championships in Athletics held in Moscow in August 2013, finishing behind Mohammed Aman of Ethiopia and Nick Symmonds of the United States.

[9] In 2014, Souleiman also won the Bowerman Mile at the Prefontaine Classic, held at Hayward Field in Oregon with a time of 3:47:32.