JUBA (Reuters) - Defense witnesses did not appear in court to testify on Thursday in the trial of a South African national who faces the death penalty in South Sudan on charges of conspiracy to overthrow the government.

William John Endley, a South African national and an adviser to South Sudanese rebel leader Riek Machar, stands in the dock, as his Lawyer Gar Adel Gar looks on, in the High Court in Juba, South Sudan February 13, 2018. REUTERS/Samir Bol

William John Endley served as an adviser to rebel leader Riek Machar, whose forces have been fighting those loyal to President Salva Kiir in a civil war since 2013. He was arrested in August, 2016. A verdict in his case is expected next week.

On Thursday, a high court in the capital Juba said none of the witnesses called by the defense appeared.

“The defense case is closed and the final judgment will be given on the 23rd of this month”, presiding judge Ladu Eriminio Sekwat said during the hearing.

Endley’s lawyer Gardit Abel Gar told Reuters that six witnesses had been served with a notification to testify, including a government minister.

In addition to charges of conspiracy and the supply of weapons, Endley - a retired army colonel - was accused of espionage, waging an insurgency, sabotage, terrorism and illegal entry into South Sudan.

He was charged alongside James Gatdet Dak, a former spokesman for Machar, who was handed the death sentence on Monday for incitement and conspiracy against Kiir’s government.

South Sudan, which won independence from Sudan in 2011, descended into civil war in 2013, months after Kiir fired his then deputy Machar. Tens of thousands of people have been killed and a third of the population have fled their homes.

Machar, who fled to Democratic Republic of Congo after fierce fighting broke out in Juba in July 2016, is now in South Africa under virtual house arrest.

Talks on a new power-sharing arrangement and an election are taking place in the Ethiopian capital but clashes have continued despite the signing of a ceasefire in December.

The ceasefire agreement was intended to revive a 2015 peace deal, which lasted less than a year before collapsing.

On Monday, the government accused the rebels of launching attacks in the northeastern town of Nassir.