By Patrick Goodenough | December 7, 2016 | 4:32 AM EST

U.S. ambassador to the United Nations Samantha Power. (AP Photo, File)

( – In 2008, Samantha Power urged Armenian Americans to vote for a junior senator from Illinois running for the White House, highlighting Barack Obama’s campaign pledge to recognize early 20th century atrocities against Armenians as “genocide.”

Power, at the time a senior foreign policy adviser to the campaign, described the Democratic candidate as “an acknowledger of the history” and assured the Armenian American community in a campaign video that he “can actually be trusted.”

She cited Obama’s “very forthright [campaign] statement on the Armenian genocide, his support for the Senate resolution acknowledging the genocide all these years later, his willingness as president to commemorate it, and certainly to call a spade a spade, and to speak truth about it.”

Eight years on, President Obama has yet to keep that pledge.

But with just weeks to go before he leaves office, Power – since 2013, his ambassador to the U.N. – has broken with administration policy, referring in public not merely to “genocide” in the context of the Armenian atrocities, but to its “denial.”

She did so while delivering a tribute to the late Nobel peace prize laureate Elie Wiesel at the U.S. Holocaust Memorial Museum last week. Power listed “genocide denial against the Armenians” among examples of “injustice” that persisted during Wiesel’s lifetime post-Holocaust.

“He lived to see more and more people bear witness to unspeakable atrocities,” Power said of Wiesel, who died in July, “but he also saw indifference remained too widespread.”

Power won a Pulitzer Prize for her 2002 book, A Problem from Hell: America and the Age of Genocide.

Up to 1.5 million orthodox Christian Armenians were killed as the Turkish Ottoman Empire disintegrated during World War I. The issue is highly sensitive in Turkey, a NATO ally whose government disputes elements of the historical record and denies that what it calls the “events of 1915” constituted genocide.

In 2007 and 2010, Ankara recalled its ambassador from Washington to protest congressional measures on the Armenian genocide.

More recently it reacted angrily when Pope Francis called the mass killings genocide in 2015 and again during a visit to Armenia earlier this year.

President Obama nominated Power as his ambassador to the U.N. on June 5, 2013. (AP Photo, File)

Campaigning in 2008, Obama in a statement declared his “firmly held conviction that the Armenian Genocide is not an allegation, a personal opinion, or a point of view, but rather a widely documented fact supported by an overwhelming body of historical evidence.”

“As a senator, I strongly support passage of the Armenian Genocide Resolution (H.Res.106 and S.Res.106), and as President I will recognize the Armenian Genocide,” he said.

But over the past eight years, as Armenians held commemorations each April 24, Obama chose in his annual statements not use the word “genocide” – to the frustration of Armenian American organizations and many lawmakers.

At Tuesday’s State Department briefing, a reporter cited Power’s remarks and asked spokesman Mark Toner why the administration has for eight years used synonyms and euphemisms but not the term “genocide.”

Toner began by stressing that Power’s words “didn’t reflect any kind of shift in the administration’s policy.”

“In answer to your question, look, this president, this administration, as have past administrations, have repeatedly mourned and acknowledged that 1.5 million Armenians were massacred or marched to their deaths in the final days of the Ottoman Empire,” her said.

“And we’ve also called for a full and frank acknowledgement of the facts of what happened around those deaths. And that remains our policy. I don’t want to get into terminology or how we referred to it. We acknowledged that 1.5 million Armenians were massacred, as I said, and we want to see a full historical accounting of those events.”

Toner did not respond when asked whether relations with Turkey prevented U.S. administrations from using the term.

Meeting last month with House Speaker Paul Ryan (R-Wisc.), the chairman of the Armenian National Committee of America, Raffi Hamparian, discussed legislative priorities for 2017 including “an end to U.S. complicity in Turkey’s denial of truth and justice for the Armenian Genocide.”

Turkey acknowledges that large numbers of people died a century ago, but blames war-induced causes, disease and famine, and says Christian Armenians and Muslim Turks alike were affected.

“Turkey does not deny the suffering of Armenians, including the loss of many innocent lives, during the First World War,” says the foreign ministry. “However, greater numbers of Turks died or were killed in the years leading to and during the War. Without belittling the tragic consequences for any group, Turkey objects to the one-sided presentation of this tragedy as a genocide by one group against another.”