Suriname's ex-president Desi Bouterse will be jailed after losing his appeal against a 20-year prison sentence for the murder of political opponents over four decades ago, the prosecutor's office said Thursday.

The South American country's highest court on Wednesday upheld Bouterse's 2019 conviction for the execution of 15 people -- lawyers, journalists, businessmen and military personnel -- in December 1982, two years after he took power following a coup.

In a statement, the office said it would "now proceed with the execution of the sentence" and would consult with Bouterse and his lawyer to "determine the day and date of the execution of the sentence imposed."

Bouterse, a former strongman who led two coups and also served as an elected president in the country, a former Dutch colony, has remained free awaiting the outcome of his case.

According to Suriname law, Bouterse has eight days from the appeal hearing to ask the president for clemency.

In July, Bouterse -- who remains very popular, notably with the country's poor and working classes -- said he would respect the ruling.

"Whatever it will be, I'm ready for it," he said.