The president of the Philippines threatened to arrest those refusing to get the Covid-19 vaccine at a time when the country is battling one of its worst coronavirus outbreaks.

"If you don't want to get vaccinated, I'll have you arrested then I'll inject a vaccine into your buttocks," Rodrigo Duterte, known for his coarse manner and foul language, said on Monday night during a televised address.

"Get vaccinated or I'll jail you in a cell," he said.