LOS ANGELES » Thousands were expected to march in Los Angeles on Friday to commemorate the 100th anniversary of the killings of an estimated 1.5 million Armenians under the Ottoman Empire.

Mayor Eric Garcetti was among the expected speakers at a morning rally that will be followed by a six-mile procession from the Little Armenia neighborhood to the Turkish consulate.

Protesters will demand the U.S. government acknowledge that the deaths of their ancestors constituted genocide, a term used to describe violence intended to destroy an entire group based on ethnicity, race or religion.

The event comes after President Barack Obama once again stopped short of calling the 1915 killings a genocide, going back on a campaign promise and prompting anger and disappointment among in the Armenian community.

Earlier this month, Turkey recalled its ambassador to the Vatican after Pope Francis described the killings as genocide. The European Parliament has also triggered Turkey’s ire by passing a non-binding resolution to commemorate "the centenary of the Armenian genocide."

Historians estimate that up to 1.5 million Armenians were killed by Ottoman Turks around the time of World War I. Turkey denies that the deaths constituted genocide.

"We commemorate with deep respect the Ottoman Armenians who lost their lives during the relocation in 1915 and we share in the grief of their children and grandchildren." The Los Angeles office of the Consulate General of Turkey said in a statement Thursday. "But we are against exploiting history and the sufferings for political purposes. … The term ‘genocide’ is a legally binding, morally obstructing, historically wrong and politically misused concept that prevents the discussion of the events."

Officially using the genocide designation could risk U.S. relations with Turkey, an important ally. Turkey withdrew its U.S. ambassador more than four years ago when a House panel approved a resolution branding the killing of Armenians as genocide. The resolution eventually stalled.