MANILA — President Rodrigo Duterte of the Philippines suggested on Friday that 19 police officers accused of killing a politician should spare themselves a lengthy trial and plead guilty because he planned to pardon them anyway.

“I can’t leave these officers behind. If they are convicted? No problem,” Mr. Duterte said. “They can call me and say they have been convicted, and I’ll tell the judge to pardon them all.”

He said the officers would be not only reinstated, but also promoted.

Mr. Duterte’s comments were criticized by opposition leaders and human rights groups, who have accused him of abusing his powers in a monthslong crackdown on drug dealers and users that has left thousands of people dead.

Leila de Lima, a senator and former rights commissioner who was jailed in February on what she says are trumped-up charges, said Mr. Duterte’s pledge to free the police officers was “extremely disturbing.”