Washington, Apr 25 (IANS): US President Barack Obama Thursday called for "a full, frank and just acknowledgement of the facts" relating to the massacre of 1.5 million Armenians at the hands of Ottoman Turks starting in 1915.

Despite his past promise, the president shunned again the word "genocide" in his latest observance of what he called "one of the worst atrocities of the 20th century," Xinhua reported.

"We recall the horror of what happened 99 years ago, when 1.5 million Armenians were massacred or marched to their deaths in the final days of the Ottoman Empire, and we grieve for the lives lost and the suffering endured by those men, women and children," the president said in a statement.

"I have consistently stated my own view of what occurred in 1915, and my view has not changed," he added. "A full, frank and just acknowledgement of the facts is in all of our interests."

Turkish Prime Minister Recep Tayyip Erdogan Wednesday issued a nine-language statement offering his condolences over the killings, the first ever by a Turkish leader.

The Armenians said over 1.5 million of their forebears were killed in 1915 and 1916 by the army of Ottoman Empire in a "genocide." Turkey, which does not deny that many Armenians died in clashes, disputes the number of deaths and objects to the use of "genocide" in describing the chapter.

"Peoples and nations grow stronger, and build a foundation for a more just and tolerant future, by acknowledging and reckoning with painful elements of the past," Obama said.

"We continue to learn this lesson in the United States, as we strive to reconcile some of the darkest moments in our own history, " he added, urging more Armenians and Turks to take the path.

More than 20 countries and 43 US states have officially recognised the Armenian genocide.