An Iranian taekwondo athlete withdrew from the world under 21 championships in Kenya after the competition draw placed her against an Israeli opponent in the first round.

Rozhan Goudarzi, who won a bronze medal last month in the women’s under 51 kilogram category at the Islamic Solidarity Games in Riyadh, pulled out in line with Iran’s long standing policy that bars its athletes from competing against Israelis.

Iran’s Supreme Leader Ali Khamenei repeated in a speech last year that athletes must not face Israeli opponents and called on sports bodies to compensate those who withdraw, describing such decisions as a “sacrifice” for national and religious ideals.

He said “we must not neglect the well being of this athlete,” urging officials to support competitors who refuse to take part.

The policy has been in place since 1979 and has led to athletes forfeiting matches or intentionally losing to avoid Israeli rivals. Authorities have punished athletes who violate it, including a lifetime ban issued against a weightlifter who shook hands with an Israeli competitor at an event in Poland.

Rights groups and sports analysts say the stance has contributed to a rise in Iranian athletes leaving the country in recent years, with several competing abroad under new flags or joining the International Olympic Committee’s Refugee Team.