UN divided over US measure

This, according to reports, is to allow more time for negotiations on a new measure to bolster its mandate.

Talks on a US-drafted text have been bogged down for nearly a week over provisions on sanctions, the deployment of drones and UN support for a new war crimes court set up by the African Union.

A new vote is now expected on Friday.

The council in August adopted a resolution to bolster the peacekeeping mission with a 4,000-strong regional force but Russia, China, Egypt and Venezuela abstained, citing concerns over South Sudan's sovereignty.

A Security Council diplomat said the latest US-drafted measure was opposed by Russia, China, Venezuela and more importantly, the three African countries on the council: Angola, Senegal and Egypt.

If no agreement is reached on Friday, the UNMISS mandate is likely to be extended for a month to allow for more time for negotiations, said Spanish Deputy Ambassador Juan Manuel Gonzalez de Linares.

Spain holds the presidency of the Security Council this month.

Russian Ambassador Petr Iliichev cited concerns in the draft resolution on tighter provisions for sanctions and the use of drones "which the government does not support" in Juba.

He also rejected a proposal to request reports on the establishment of the AU hybrid court, saying "the UN has nothing to do" with the proposed war crimes tribunal.

Rift over sanctions

The United Nations has some 14,000 peacekeepers serving in South Sudan, where a brutal war has been raging since December 2013.

"We are working toward the strongest mandate renewal possible to give UNMISS the tools it needs to carry out its mission," said a US official, speaking on background.

The struggling talks on the draft resolution came as the United States, Britain and France continued to face opposition at the Security Council from Russia and China on imposing an arms embargo on South Sudan.

Angola's Ambassador Ismail Gaspar Martins said the council must adopt measures to engage with South Sudan's leadership to try to end the war, signaling his opposition to sanctions.

"We cannot repeat the same resolution that was adopted some time ago," he told AFP.

"It has to be something that takes account of the situation and gets people in South Sudan engaged in working on a plan which brings about a more peaceful situation in the country."

UN Secretary-General Ban Ki-moon last month warned that South Sudan faces a "very real risk of mass atrocities" and that peacekeepers would be powerless to stop such a bloodbath.

The peacekeepers have come under heavy criticism for failing to protect civilians, including women who were raped by government soldiers during heavy fighting in July, not far from the gates of a UN compound in Juba.

The conflict has killed tens of thousands of people and displaced more than 2.5 million.