"The President recognizes the deep significance of the Jewish experience especially their tragic and painful history," presidential spokesman Ernesto Abella said a statement. "We do not wish to diminish the profound loss of 6 million Jews in the Holocaust -- that deep midnight of their story as a people."
Abella said Duterte's opponents first brought up the Hitler reference before the May presidential election to "gain political mileage."
"The President's reference to the slaughter was an oblique deflection of the way he has been pictured as a mass murderer."
The statement said Duterte likewise drew an "oblique conclusion, that while the Holocaust was an attempt to exterminate the future generation of Jews, drug-related killings as a result of legitimate police operations ... will nevertheless result in the salvation of the next generation of Filipinos."
Abella said the Presidential Palace "deplores the Hitler allusion of President Duterte's anti-drug war as another crude attempt to vilify the President in the eyes of the world."
'Save the next generation from perdition'
In a speech Friday in his hometown of Davao City, Duterte said, "Hitler massacred 3 million Jews. Now there is 3 million, what is it, 3 million drug addicts (in the Philippines), there are.
"I'd be happy to slaughter them. At least if Germany had Hitler, the Philippines would have (me). You know my victims, I would like (them) to be all criminals, to finish the problem of my country and save the next generation from perdition."
The US Holocaust Museum
in Washington describes the Holocaust as "the systematic, bureaucratic, state-sponsored persecution and murder of 6 million Jews by the Nazi regime and its collaborators." The Nazis also targeted other groups such as Gypsies, the disabled, some Slavic peoples, communists, socialists, Jehovah's Witnesses and gays.
'These statements are revolting'
World Jewish Congress President Ronald Lauder condemned Duterte's remarks while in Israel on Friday to attend the funeral of former Israeli Prime Minister Shimon Peres
"These statements are revolting, and President Duterte must retract them and apologize," Lauder said. "We just marked the 75th anniversary of Babi Yar, the massacre of more than 33,000 Jews in Ukraine by Nazi Germany. ... Now, the elected leader of the Philippines openly calls for the mass murder of people who are addicted to drugs.
"Drug abuse is a serious issue. But what President Duterte said is not only profoundly inhumane, but it demonstrates an appalling disrespect for human life."
Also Friday, US Defense Secretary of Defense Ash Carter called the comments "deeply troubling" after a meeting of defense ministers from the Association of Southeast Asian Nations in Hawaii. Carter told reporters that Duterte's remarks were not discussed at the meeting.
He said that US-Philippines cooperation "has served the interests of our nations for many years now" and added that he had good discussions about "ongoing alliance operations" with his counterpart from the Philippines.
US State Department spokesman Mark Toner echoed Carter's description of Duterte's remarks.
Toner told reporters Friday in Washington that the US-Philippines relationship was based on "our shared belief in human rights and human dignity, and within that context, President Duterte's comments are a significant departure from that tradition."
"Words matter, especially when they're from leaders of sovereign nations," he said.
Hard-line stance on drugs
The controversial Philippines leader campaigned on a hard line against crime, particularly drug offenses, and has uttered statements causing the international community to recoil.
Since taking office in June, Duterte has stood by his promise to crack down on crime, with hundreds of suspected drug users killed by his police force, along with hundreds of other deaths attributed to vigilante killings.
Police have made thousands of arrests and have implemented a controversial "knock and plead" policy of visiting suspected drug users in their homes and inviting them to register as users with their local community officials.
Duterte is known for making blunt and outrageous comments. He's joked about not being able to join the gang rape of an Australian missionary, cursed Pope Francis and called both US President Obama and the US ambassador to the Philippines a "son of a bitch." He has told police they can kill drug dealers if they fight back.
Duterte defends himself
Duterte has defended himself against criticism from the United States and European Union, which have expressed concerns about his war on drugs and allegations of extrajudicial killings.
"You, US, EU, you can call me anything, but I was never into or I am never into hypocrisy like you. Close your doors and when there's time, there are migrants escaping from the Middle East," Duterte said.
"You allow them to rot. And then you're worried about the deaths of a 1,000, 2,000, 3,000?
"That's why if you were in my position, why would you not curse? You are portrayed or pictured to be some, a cousin of Hitler, and yet do not even bother to find out to investigate this."