Philippine President Rodrigo Duterte refused to back down Saturday over his stated desire to slaughter millions of people, as global condemnation built against him likening his crime war with Hitler's efforts to exterminate Jews. Duterte on Friday drew parallels with the Nazi's mass murder of Jews and his anti-drug crackdown, which has left more than 3,000 people dead and raised concerns about the rule of law crumbling in the chaotic Asian democracy. Facing a fierce international backlash, Duterte's spokesman released a statement insisting the president did not want to be compared with Nazi leader Adolf Hitler but confirmed he was prepared to kill three million people in his crime war. "The president's reference to the slaughter was an oblique deflection of the way he has been pictured as a mass murderer, a Hitler, a label he rejects," said presidential spokesman Ernesto Abella Nevertheless, Abella confirmed Duterte had intended to say he wanted to kill millions of people in the Philippines to achieve his mission of eradicating illegal drugs. "Duterte was referencing to his ‘willingness to kill' three million criminal drug dealers – to save the future of the next generation and the country," Abella said. The United States condemned his Hitler comments. "I'll stress that it (relationship) has to be one that's based on shared values, democratic values, respect for human rights, and words matter," US State Department deputy spokesman Mark Toner said in Washington. "And within that context, President Duterte's comments are a significant departure from that tradition. And we find them troubling." US Defence Secretary Ashton Carter also described Duterte's comments as "deeply troubling." The United Nations special adviser on the prevention of genocide, Adama Dieng, warned in a statement that Duterte may be in danger of committing crimes against humanity. Dieng called on Duterte to "exercise restraint in the use of language that could exacerbate discrimination, hostility and violence and encourage the commission of criminal acts which, if widespread or systematic, could amount to crimes against humanity." Phelim Kine, deputy Asia director for Human Rights Watch called on the US and the European Union to act, saying Duterte's comments could further embolden police and other armed groups to "lawlessly slaughter" fellow Filipinos. At home, Duterte congressional allies Sarah Elago and Marjohara Tucay of the small Kabataan (Youth) party drew the line on the Hitler comments. "When it comes to your independent foreign policy... we can lend you unequivocal support. But if you start comparing yourself to Hitler, we will not have any of it," they said in a statement. Duterte has in recent months faced relentless criticism from Western governments and rights groups over the apparent extrajudicial killings. US President Barack Obama called on Duterte to fight his drug war "the right way," and respect the rule of law. Duterte, 71, has typically reacted with defiance abusive language to his critics, while insisting he is not doing anything illegal. Duterte has branded Obama a "son of a whore," called UN chief Ban Ki-moon a "fool" and said "fuck you" to the European Union while raising his middle finger.