World Bulletin / News Desk
The amnesty announcement was read out on state-run television late on Wednesday.
It follows an agreement signed by South Sudan’s warring parties that grants the opposition power in a transitional government to end the young nation’s five-year bloody civil war that claimed tens of thousands of lives.
The agreement states that Kiir stays president and Machar will return to the country as the first vice president alongside five others.
"This genuine offer was made by his Excellency in the interest of peace so it would be wise if they (rebels) response to this call by the president," Michael Makuei, the government spokesman and information minister, told Anadolu Agency.
Since the beginning of the South Sudan civil war in 2013, tens of thousands have been killed and hundreds of others have been kidnapped, arrested and unlawfully detained, mostly by forces loyal to President Kiir but also by the opposition pitted against him.
Paul Lam Gabriel, a spokesman for Machar, rejected the offer as "meaningless" and "a blank cheque".
He said Kiir had issued amnesties in the past, including one in 2016, but no political prisoner or opposition member had benefited from it.
"He (Kiir) is using this to whip up support from the international community and the region". "If the government is serious about this amnesty, they should free political detainees in Juba."
South Sudan slid into chaos in 2013 when President Kiir accused his ex-deputy Machar of a coup, an accusation Machar denied.
The war engulfed the whole country, spurring a new wave of violence that fueled Africa’s biggest refugee crisis and displaced 4 millions people from their homes, including 2 million refugees who sought shelter in neighboring countries.