While the Philippines government seems to be banking heavily on military treaties with the US as they confront China over maritime disputes, relations between the two nations are starting to show some weakness, as President Obama pointedly canceled his planned meeting with his Philippines counterpart, Rodrigo Duterte.

The notoriously outspoken Duterte, when asked about the possibility of President Obama bringing up the growing number of extrajudicial killings by security forces in their war on drugs, went on a tirade against the US president, declaring him to be a “son of a whore,” and insisting that he is no American puppet that a US president can question like that.

It wasn’t clear that Obama even planned on asking about the summary executions, and indeed with the Philippines recently restoring US military access to their soil, the president likely would’ve tried to avoid any major blow-ups. Instead, the blow-up happened before the talks, and Obama quickly cancelled them outright, saying he didn’t want to meet if there was nothing productive to discuss. He also warned that if they do meet in the future, he’ll definitely bring up the executions now.

Duterte, who was elected president back in June, was seen as a “law and order” candidate, who publicly declared his support for vigilantism and summary executions as effective anti-crime measures. He bragged upon his election that allegations of 1,000 killed during his tenure as Davao City mayor would become 100,000, and that he would dump the corpses in Manila Bay. Virtually from the moment of his election, police have begun executing suspected drug dealers, and even some users, with impunity.