Armenian President Serzh Sargsyan (right) and U.S. actor George Clooney (center) during the Aurora Prize ceremony in Yerevan, April 24, 2016. 100 Lives Foundation

YEREVAN, Armenia — Hollywood A-Lister George Clooney has become the latest U.S. celebrity to speak out over the Armenian genocide as he visited the South Caucasus country to mark the 101st anniversary of mass killings in the Ottoman Empire and present a new humanitarian prize.

Clooney awarded the $1 million Aurora Prize to Burundi orphan worker Marguerite Barankitse at a ceremony in Yerevan and told guests, including Armenian President Serzh Sargsyan, that the “whole world” remembered the Armenian genocide.

"We honor the million and a half lives that were lost 101 years ago. And we honor those lives by calling their tragedy by its true name. Genocide. The Armenian Genocide," Clooney said.

Historians maintain Ottoman ethnic cleansing of Armenians in what is now eastern Turkey and northern Syria during the First World War killed about 1.5 million people and amounted to the first genocide of the 20th century. But Turkey, the successor state to the Ottoman Empire, characterizes events as civil unrest, claims the death toll has been vastly inflated and virulently denies that the crimes constitute a genocide.

Clooney’s intervention comes one year after U.S. celebrity Kim Kardashian made headlines when she visited Yerevan with her husband Kanye West during a trip to re-discover her Armenian roots. Kardashian has also urged the world to recognize the Armenian genocide.

U.S. television personality Kim Kardashian (center) with her daughter North West in hand walks during their visit to Armenia, April 11, 2015. Reuters

As well as presenting the Aurora Prize, during a ceremony at the city’s imposing genocide memorial overlooking Yerevan — comprising of 12 stone slabs positioned in a circle with an eternal flame dedicated to the memories of the victims at its center — Clooney paid his respects to the Armenians who died.

“It’s ridiculous not to talk about it in terms of genocide because of course it was,” Clooney told reporters after he arrived in the Armenian capital Thursday.

Armenians all over the world mark April 24, the day when hundreds of Armenian intellectuals were killed in Istanbul in 1915, as Armenian Genocide Memorial Day. Commemoration events in Yerevan included a march by over 10,000 people carrying candles and Armenian flags through the city center, calling on countries, including the United States and the United Kingdom, to publicly recognize the genocide. Demonstrators also trampled Turkish flags.

Turkey "has not changed its hostile stance toward everything that is Armenian," Sargsyan said in a statement to mark the occasion, the Agence France Presse news agency reported.

A woman carries a candle holder with a printed Armenian flag on it during a march to commemorate the 101st anniversary of the mass killing of Armenians by Ottoman Turks in Damascus, Syria April 22, 2016 Reuters

U.S. President Barack Obama provoked widespread condemnation by Armenian-Americans last week when he declined to call the events during the First World War a genocide, referring to them instead as the “first mass atrocity of the 20th century” in a statement Thursday. During his campaign for the presidency in 2008 Obama pledged to recognize the attacks as genocide if elected to the White House.

The reluctance of many Western countries to use the word genocide in the case of the Armenians stems from a desire to avoid damaging their relationships with Turkey, a key regional ally.

Fighting in neighboring Syria and an uptick in violence between Turkish security forces and the local Kurdish population in eastern Turkey has re-opened old wounds and prompted fears in Yerevan of Turkish aspirations in the region. A collapse in relations between Moscow and Ankara over the downing of a Russian jet over Syria has also created fresh tensions in the South Caucasus, where Russia and Turkey have traditionally sparred for influence.

Clooney was visiting Armenia in his role as the co-chair of the Selection Committee for the Aurora Prize, a new award funded by Russian-Armenian philanthropist and businessmen Ruben Vardanyan. The winner of the inaugural prize, Barankitse, was recognized for her work with children and refugees during years of civil war in the landlocked African country of Burundi.