JUBA, Feb. 23 (Xinhua) -- A South Sudan court on Friday sentenced to death by hanging a South African national and security advisor to rebel leader Riek Machar.

The South Sudan High Court said William John Endley, a retired soldier of the South African army, holds the rank of major general in the main rebel group the Sudan People's Liberation Army-in opposition (SPLA-IO).

Endley's charges included illegal entrance, sabotage, conspiracy and terrorism.

Judge Ladu Eriminio Sekwat said Endley will subsequently serve a 9-and-half-year jail sentence.

Endley has already served one and half year in detention since being arrested in August 2016 in Juba after renewed fighting broke out between Machar's faction and troops loyal to President Salva Kiir.

Endley's lawyer Gardit Abel Gar said they would launch an appeal.

"It is inconsistent with the just signed Cessation of Hostilities (CoH) which has expressly stated that all political prisoners of war should have been released within 72 hours," Gar said after court rejected his plea for lenient sentence for Endley on medical reasons.

The court said evidence got from Endley's confiscated laptop showed he had passed on information aiding the opposition in military engagement against the South Sudan government.

The same court on Feb. 12 sentenced to death James Gatdet Dak, Machar's spokesman captured and extradited to Juba from Nairobi in November 2017.

"The UN has very firm view that we do not support the death penalty," said the head of the UN Mission in South Sudan (UNMISS) David Shearer on Thursday in reference to the trials.

South Sudan descended into violence in December 2013, after political dispute between President Kiir and his former deputy Machar led to fighting that pitted Dinka ethnic soldiers loyal to Kiir against Machar's Nuer ethnic group.

The 2015 peace agreement to end the violence was again violated in July 2016 when the rival factions resumed fighting in the capital, forcing Machar to flee into exile.

The conflict has killed tens of thousands of people and displaced millions that have sought refuge in neighboring countries.