New York - The United Nations peacekeeping chief Herve Ladsous is pleading with the Security Council to impose an arms embargo on South Sudan where he expects an upsurge in fighting with the coming end of the rainy season.Ladsous told reporters that he had made his appeal directly to the council during a closed-door meeting on Monday."I think an arms embargo should happen now and that's even very late," Ladsous told reporters on Tuesday."The rainy season is coming to a close and that has frequently been the time of the year when people go back to military operations."The council is weighing its next steps in South Sudan after the government in Juba showed little cooperation with UN plans to deploy a 4 000-strong regional force.The council voted in August to deploy the force in Juba and warned that if the government opposed the plan it would face an arms embargo.Significant limitations Prospects for peace in South Sudan faded when rebel leader Reik Machar, who had been appointed vice president of a new unity government, fled Juba following heavy fighting in July.Follow News24 Africa on Facebook and Twitter. Machar has been replaced by Taban Deng Gai and is now in South Africa for medical treatment. He has called for renewed war with the SPLA forces of President Salva Kiir."On the SPLA side, they do entertain the idea that they could achieve a military victory, so the political process comes second," a senior UN official said.South Sudan descended into war in December 2013 after Kiir accused his former deputy Machar of plotting a coup.Tens of thousands of people have died and more than 2.5 million have been driven from their homes in the nearly three-year war, which has been marked by appalling levels of rape and killings.The UN Secretary General Ban Ki-moon said in a letter to the council last week that Kiir's government was imposing "significant limitations" to the proposed new force.Ethiopia, Kenya and Rwanda have offered to contribute troops, but the Juba government has yet to give its approval for the makeup of the force, which will be under the command of the UN mission in South Sudan.