Philippines President Rodrigo Duterte has compared himself to Adolf Hitler, saying he wants to kill millions of drug addicts, just as the Nazi leader killed Jews during the Holocaust.

"Hitler massacred three million Jews. Now there is 3 million, what is it, 3 million drug addicts (in the Philippines), there are," CNN quoted the President as saying in a speech on Friday in his hometown of Davao city.

"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."

World Jewish Congress President Ronald Lauder, in Israel to attend the funeral of former Prime Minister Shimon Peres, condemned the remarks.

"These statements are revolting, and President Duterte must retract them and apologise," 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," Lauder added.

Since taking office in June, Duterte has stood by his promise to crack down hard on crime, with hundreds of suspected drug users killed by his police force, alongside hundreds of others deaths attributed to vigilante killings.