Kim Kardashian has launched an outspoken attack on President Obama for refusing to use the word 'genocide' as he marked the 100th anniversary of the massacre of 1.5 million Armenians. The reality star said it was 'very disappointing' that he stopped short of using the word - which he had promised to use when he ran for office. Kardashian, whose Armenian heritage comes from her father, the late Robert Kardashian, has used her celebrity since  2011 to bring awareness to the genocide. Marking the anniversary of the mass murder at the weekend, Kardashian wrote in an op-ed in Time magazine: 'I would like President Obama to use the word "genocide". It’s very disappointing he hasn’t used it as President. 'We thought it was going to happen this year. I feel like we’re close — but we’re definitely moving in the right direction. ' Scroll down for video . Kim and Khloe Kardashian laid flowers at the Dzidzernagapert Armenian genocide monument’s eternal flame during their April 10 visit. Marking the anniversary of the mass murder last weekend, Kim Kardashian wrote in an op-ed, 'I would like President Obama to use the word “genocide.” It’s very disappointing he hasn’t used it as President' Tricky language: President Barack Obama sent an administration official to Armenia to mark the 100th anniversary of the 1915 massacre by Ottoman Turks. But he refused to call the mass killings of ethnic Armenians a 'genocide' for fear of offending ally Turkey . Slaughter: Historians estimate that 1.5 million Armenians were killed by Ottoman Turks during World War I. Above, Armenians are made to march in this picture from the 1915 massacre . Kim and Khloe walk in the plaza at the Armenian Genocide Memorial. They were accompanied by their cousins Kara and Kourtni and Kim's husband Kanye West. Kim and Khloe's  Armenian heritage comes from their father, the late Robert Kardashian . As a senator and presidential candidate, Obama did describe the killings of Armenians as genocide. But he has never used that description since taking office, mainly out of deference to Turkey, a key U.S. partner. The White House said U.S. officials pledged to Armenian-American leaders that the U.S. would use last week's 100th anniversary of the killings 'to urge a full, frank and just acknowledgement of the facts,' but a statement about the meeting did not include the word 'genocide.' Historians estimate up to 1.5 million Armenians were killed by Ottoman Turks, an event widely viewed by scholars as a genocide. Turkey, however, denies that the deaths constituted genocide because it was not an ethnic-driven battle and says the death toll has been inflated. Democratic Rep. Adam Schiff also said he was 'deeply disappointed' by the president's decision. 'The United States has long prided itself for being a beacon of human rights, for speaking out against atrocity, for confronting painful chapters of its own past and that of others,' said Schiff. 'This cannot be squared with a policy of complicity in genocide denial by the president or Congress.' Kardashian, who recently traveled to the country for the first time with her husband Kanye West, sister Khloe and cousins Kara and Kourtni Kardashian, said, 'Now is the time to speak out, and every little bit helps' 'I will continue to ask the questions and fight for the genocide to be recognized for what it was,' the reality television star said, encouraging Turkey to label the killings as a genocide. 'It’s not the fault of the people who live there now, ' she noted, and 'I think if they recognize it and acknowledge it, everyone can move on. 'I believe in moving on and looking toward a brighter future, but you can’t move on unless you acknowledge the past. To not do so is an act of disrespect.' Paying their respects: Kim has used her celebrity status to bring awareness to the genocide since at least 2011. The Pope has also called the slaughter 'the first genocide of the 20th century' Kim and Kanye are pictured here with daughter North West and Khloe as they walk inside church hallways to view art prior to baptism in at Cathedral of Sts. James in the historic Armenian Quarter of the Old City of Jerusalem last year for Norrie's christening . Kardashian recalled in the op-ed that her family tree would have ended if her grandparents hadn't left Armenia for Los Angeles the year before the armed conflict. 'There are so many people who lost their families, and the stories of how they were killed are so heartbreaking—they should never be forgotten,' she wrote. 'The whole point of remembering the genocide is to make sure it doesn’t happen again. A million-and-a-half people were brutally massacred, and a country can just pretend like it never happened? I don’t think that’s right.' While in Armenia, Kardashian and her family visited the Dzidzernagapert Armenian Genocide monument’s eternal flame that honors those countryman who were killed in 1915. 'An emotional day at the genocide museum,' read a tweet posted by Kim that was accompanied by a photo of her and Khloe laying flowers at the flame. Kardashian has been publicly calling for the deaths to be recognized as a genocide since 2011, when she wrote in a blog post, 'Every year, I honor the memory of the martyrs who were killed during the 1915 Armenian Genocide. Even though so many countries around the world recognize the Genocide, the government of Turkey still denies it. 'It happened before Rwanda, Darfur, and the Holocaust. Maybe none of those other genocides would have happened if more nations had condemned the Armenian Genocide, when 1.5 million Armenians were massacred.' During their trip to her ancestors' homeland, Kim, Khloe and their cousins met with the country's Prime Minister, Hovik Abrahamyan, who 'expressed how proud they are that we are proud Armenians and we have not forgotten our roots!' Kim said in a tweet. Kim's husband Kanye also threw an impromptu bash and free concert in Yerevan at Swan Lake before departing Armenia for Jerusalem, Israel - the location of their daughter's christening at an Armenian church in 2014. The Kardashians also visited the Geghard Monastery during their trip to Armenia . Khloe wrote in a tweet on the day of their visit to the genocide memorial: 'My sister and I are trying to bring awareness not only to our Armenian genocide but genocides and human slaughter, in general. Knowledge is power!' 'The Kardashians have helped strike a powerful blow at Turkey's campaign of genocide denial,' ANCA communications director told ABC News after the visit. Their trip to Armenia 'has helped shine a global spotlight' on the genocide and 'the need for justice for that crime with millions,' she said. Khloe also kept the campaign going after she returned home, asking her fan base on Twitter to sign a Change.org petition 'to bring awareness to the Armenian genocide' by requesting that Google highlight the conflict with its homepage doodle on the anniversary of the killings, April 24. 'I did!!!' she said. As of Friday  the online petition had garnered more than 202,129 supporters, beating its goal of 200,000 names. Google did not wade in the controversy by adopting the suggested doodle, however. The White House said last week that while it understands the perspective of those hoping to hear different language from Obama this year, the administration believes its approach is right, 'both for acknowledging the past, and for our ability to work with regional partners to save lives in the present.' It announced at the same time that Treasury Secretary Jacob Lew would attend a ceremony in Armenia on Friday making the anniversary. 'President Obama's surrender to Turkey represents a national disgrace,' Armenian National Committee of America Chairman (ANCA) Ken Hachikian said in a statement. 'It is, very simply, a betrayal of truth, a betrayal of trust.' The Pope added his name this year to the list of high-profile leaders characterizing the 1915 slaughter as the 'first genocide of the 20th Century.' He further proclaimed that 'concealing or denying evil is like allowing a wound to keep bleeding without bandaging it.' Ties that bind: The Kardashian family tree that traces back to two Molokan Armenian families . Home: Kim Kardashian's ancient ancestors fled the Armenian village Karakale (pictured recently) to escape a prophecised genocide that DID come to pass . Genocide: The village of Karakale (pictured in the 19th Century) was among hundreds destroyed as the Ottoman Empire laid waste to the region. Residents - possibly including the Kardashians - can be seen standing by their traditional houses . Disputed: Armenian lands (in red) were disputed just after the turn of the 20th Century, with bloody consequences . Armenians say up to 1.5 million of their kin were killed between 1915 and 1917 as the Ottoman Empire was falling apart and have long sought to win international recognition of the massacres as genocide. Turkey rejects the claims, arguing that 300,000 to 500,000 Armenians and as many Turks died in civil strife when Armenians rose up against their Ottoman rulers and sided with invading Russian troops. The fundamental division was religious. Armenians are Christians, while Turks are Muslims. The two groups had lived alongside each other for hundreds of years, but the Ottoman Turks had always been on top. As Ottoman rule crumbled, rival nationalisms arose, and the Russian Empire - itself to experience revolution in 1917 - also invaded. Armenians say they were forced from their homes, marched to mass graves and slaughtered. Some managed to flee south into modern-day Syria and the Levant, others to Russian-held land which is now modern-day Armenia. Hundreds of thousands met a violent end or died as they fled. The outcome in terms of mass death is not now widely disputed. But the use of the word 'genocide' is hugely controversial, as Turkey - successor to the Ottoman empire, and with a huge majority of Muslim ethnic Turks - rejects the description. Armenia, which became a fully-fledged nation in its modern form at the collapse of the Soviet Union, has campaigned for recognition of its description of the deaths. Its modern borders are much smaller than the areas where the deaths occurred. The province of Kars (above), where the Kardashians' roots - and the origin of their name - lies, is almost entirely in Turkey. Its capital, Kars, is now a symbol of the division over the deaths between the two countries: it sits on the border but the frontier is closed.
In 1915, 1.5 million Armenians were killed by Ottoman Turks in what historians have described as the first genocide of the 20th century.
Obama refused to call the mass killings a 'genocide' in  official statement despite promising as a presidential candidate that he would.
Turkish officials furiously deny there was a genocide, and Obama has shied away from offending the close U.S. ally.
Kim Kardashian - who is Armenian on her father's side - has called the killings a genocide and says Obama should too.
Kasdashian recently traveled to the country for the first time with her husband Kanye West, sister Khole and cousins Kara and Kourtni.