YEREVAN, Armenia — An American doctor who has spent years working in a fighting-ravaged region of Sudan has been awarded the $1.1-million Aurora Prize for exceptional humanitarianism.

Dr. Tom Catena was presented the prize Sunday in Armenia’s capital, Yerevan. The prize was established in remembrance of the Armenian survivors of a mass killing by Ottoman Turks.

An estimated 1.5 million Armenians were killed in 1915-23 in what many historians regard as the first genocide of the 20th century, a claim that Turkey rejects.

Catena, based in Sudan’s Nuba Mountains, “is a role model to us all,” said American actor George Clooney, co-chairman of the prize selection committee and a prominent advocate of recognizing the killings as genocide.

The prize includes $100,000 for Catena and $1 million for him to donate to organizations of his choice.