Noting that Hitler had murdered millions of Jews, Duterte said: "There are three million drug addicts (in the Philippines). I'd be happy to slaughter them.
"If Germany had Hitler, the Philippines would have...," he said, pausing and pointing to himself.
"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."
Duterte was voted to power in a May election on the back of a vow to end drugs and corruption in the country of 100 million people. He took office on June 30 and over 3,100 people have been killed since then, mostly alleged drug users and dealers, in police operations and in vigilante killings.
Two days before the Philippines election, outgoing President Benigno Aquino had warned that Duterte's rising popularity was akin to that of Hitler in the 1920s and 1930s.
"I hope we learn the lessons of history," Aquino said in widely reported remarks. "We should remember how Hitler came to power."