Warring parties in a civil conflict that is now in its sixth year, agreed Friday to delay the formation of a power-sharing government from May 12 for six months, after implementation of a peace deal ran aground.

Kiir's main rival, his former vice president Riek Machar, had pushed for the delay, while Kiir wanted to move forward with the unity government and deal with outstanding issues later.

However as questions mount over Kiir's political will to implement the September 2018 peace deal, the president said even the extension would not be enough to resolve sticky issues such as creating a unified army and agreeing on state boundaries.

"If we cannot do them in the last eight months, what will make this succeed this time around in six months?" Kiir told officials while launching the country's new civil registry.

"I told my team (in Addis Ababa)... that instead of six months, let us call for a one-year delay," due to seasonal rains from May to November which make the country's largely dirt roads impassable.

Kiir accused Machar of continuing to recruit fighters during a ceasefire which has largely held since September.

"He is now recruiting and this recruitment is prohibited in the agreement and if it is a matter of recruitment, it does not cost me much to also recruit," he said.

The United Nations has accused all sides of continuing to recruit fighters.

South Sudan's war broke out in 2013, two years after independence, after Kiir accused his Machar of plotting a coup against him.

The fighting has left 380,000 people dead and forced more than four million South Sudanese -- almost a third of the population -- to flee their homes. Numerous attempts at peace have failed.

Kiir's latest comments come a week after it emerged he had hired an American lobby firm to block the formation of a hybrid African Union-South Sudan court to try war crimes, stipulated in the peace agreement.