Mekkonen attended the 1999 and 2001 World Championships in Athletics and represented Ethiopia at the 2000 Summer Olympics, but he failed to make the podium at any of the events. His form improved in 2002 and he won the short race bronze and team silver at the World Cross Country Championships. He focused on the track in 5000 m the next year and won the 2003 All-Africa Games silver and the 2003 Afro-Asian Games gold medal. After a long time out of the spotlight of international competition he re-emerged in 2009 after switching to the half marathon and marathon.
Competing at his first IAAF World Indoor Championships, he finished seventh in the final of the 1500 m. After this he decided that he would not succeed over distance and permanently switched to the 5000 m, saying: "That’s enough for the 1500. It was tried, it didn’t work."[4] Returning to the cross country championships, he improved to win the team silver at the 2001 edition, although he finished tenth overall. He finished eighth in the 5000 m at the 2001 World Championships in Athletics. He was selected for the 2001 IAAF Grand Prix Final, but he only managed eighth place in the 3000 m final. He also took part in the 5000 m at the 2001 Goodwill Games, just missing out on the medals in fourth.[5] He began taking part in road races and won the Memorial Peppe Greco 10 km. He had his best ever cross country result at the 2002 edition in Belfast, winning a bronze medal for himself and helping Ethiopia to the team silver in the short race. He ran in the QSI 10 km and was second behind Haile Gebrselassie who set a world best for the distance.[6]
At the 2003 All-Africa Games, he decided not to defend his 1500 m title and instead opted for the 5000 m and he won the silver medal, just beaten by Kenenisa Bekele.[7] He travelled to Hyderabad in India to compete at the 2003 Afro-Asian Games, where he won the gold in the 5000 m. He took part in the 2003 International Chiba Ekiden and was the fastest runner in the second stage and helped Ethiopia to victory in the fastest ever Ekiden race.[8]
From 2008 onwards, he began to focus more on road running competitions. After a long absence from major international competition, he signed up for the 2009 IAAF World Half Marathon Championships.[9] However, he failed to finish the race. He finished second at the Great Scottish Run behind Jason Mbote in late 2009.[10] The following year, he took eighth place at the 2010 Paris Marathon and even though he fell over midway through the race, he recovered to set a personal best of 2:09:01.[11] Further improvement came at the Amsterdam Marathon where, despite finishing in fifth, he ran almost a minute and a half faster than his previous best by completing the race in 2:07:37.[12]
He cut another two seconds off his best with his winning time at the 2011 Tokyo Marathon in February.[13] He was runner-up at the Montferland Run that year, being beaten to the title by Philip Langat.[14] He returned to defend his title at the 2012 Tokyo Marathon, but could manage only eighth place on that occasion.[15]
on September 22, 2012 he won the heng shui marathon in 2:08.05
