By Agencies

Riek Machar's group says extending Salva Kiir's term until 2021 undermines peace talks with opposition forces.

South Sudan opposition has described as illegal plans to extend the tenure of President Salva Kiir by three years.

Opposition spokesman Lam Paul Gabriel called the proposal "definitely illegal" and "anti-peace" as the warring sides pursue a peace agreement.

Gabriel told journalists in the capital, Juba, on Tuesday that the plot to keep Kiir in office until 2021 undermines peace talks with opposition forces.

The South Sudanese presidency on Monday proposed a bill to parliament to amend the constitution and extend the tenure of President Salva Kiir, his deputies and governors, Paul Yoane Bonju, a member of parliament said.

The parliament intends to vote it into law this month, Bonju said.

Another lawmaker Atem Garang said the planned extension of Kiir's term is almost guaranteed as the ruling party holds a majority of seats in parliament.

"If they don't extend it there will be anarchy and war. You'll have a country without a government," Garang told The Associated Press.

South Sudan's President Salva Kiir and his opponent Riek Machar agreed, at talks in the Sudanese capital Khartoum last Wednesday, to a "permanent" ceasefire to take effect within 72 hours, raising hopes of an end to a devastating civil war.

The latest ceasefire was violated hours after it began with the government and armed opposition trading blame.

The previous ceasefire in December was violated within hours as well, prompting a new push by the international community to threaten UN and regional sanctions against those blocking the path to peace.

South Sudan's civil war has killed tens of thousands and created Africa's largest refugee crisis since the 1994 Rwandan genocide.

Both sides have been accused of abuses including gang-rapes, sometimes along ethnic lines.

Millions are near famine and aid delivery is often blocked in one of the world's most dangerous countries for humanitarian workers.

The conflict erupted in 2013; around two years after South Sudan won independence from Sudan, when Kiir accused his then-deputy Machar of plotting a coup.