Philippine President Rodrigo Duterte. Thomson Reuters President Donald Trump appeared to endorse Philippine President Rodrigo Duterte's brutal campaign against suspected drug dealers, according to a transcript of an April phone conversation between the two.

Trump praised Duterte for doing "an unbelievable job on the drug problem" in the Philippines, according to the transcript cited by The Washington Post. The US president's comments raised some alarm because Duterte's regime has made a publicly hailed the killings of thousands of suspected drug dealers.

“Many countries have the problem," Trump told Duterte regarding illegal drug-dealing. "We have the problem, but what a great job you are doing and I just wanted to call and tell you that,” Trump said.

Extrajudicial executions have been running rampant in the country since Duterte assumed office in 2016, sparking an outcry from US allies, such as the European Union, to halt the violent campaign that has seen at least 4,500 deaths in the last five months alone.

The apparent warming relationship between Trump and Duterte is a stark contrast to interactions between the Philippine president and former President Barack Obama.

Duterte once called Obama a "son of a whore" and lectured him on the US' history of colonialism after Obama criticized his war of drugs. The relationship between Obama and Duterte further deteriorated when Duterte called for the the end of military exercises between the countries, and the removal of US Special Operations troops from the island of Mindanao.