Born on December 18, 1956, Khalifa is a former Sudanese middle distance runner who set a national record of 3:33.28 minutes over 1500 meters in Grossetto in 1986. Prior to this, he won silver medals in the 800 m and 1500 m races at the Olympic Boycott Games in 1980. Khalifa won the 1500 m race at the World Cup 1985 in Canberra. He finished fifth in the 1500 m final at the 1987 World Championships in Athletics in Rome and eighth in the 1984 Summer Olympics in the same event. He also competed at the 1988 Summer Olympics, finishing 12th.