“My condolences go out to the family and friends of Kian (Delos Santos). Hope that the investigations lead to full accountability,” US ambassador Sung Kim said on his Twitter account.
Duterte has said relations with the United States are better under Donald Trump, who has praised him for doing an “unbelievable job on the drug problem.”
Kim, who has been the ambassador since late last year, had sought to repair relations strained after his predecessor intervened in Philippine affairs, according to Duterte.
Police said Delos Santos was a drug courier who fired at them while resisting arrest.
However CCTV footage emerged of two policemen dragging who appears to be the unarmed boy away moments before he was killed.
The public attorney’s office on Monday said a forensic investigation found Delos Santos was shot in his back and ear, and that the evidence pointed to an “intentional killing.”
“Whether or not he was involved in the use or trafficking of illegal drugs, he did not deserve to die in the manner that he did,” Defense Secretary Delfin Lorenzana said in a statement.
“If the allegations of foul play are proven then the perpetrators must be brought to justice.”
The Senate on Thursday will begin its investigation into Delos Santos’ death.
Duterte on Monday said policemen who killed Delos Santos would be jailed if convicted. Agence France Presse
