The United States has launched a bid at the Security Council to impose an arms embargo on South Sudan following UN warnings that the war-torn country could descend into genocide. <br/><br/>US Ambassador Samantha Power said yesterday a draft resolution will be presented in the coming days to ban weapons sales to the country, setting the stage for a clash with Russia and other opponents of an arms embargo. <br/><br/>The move came after UN Secretary-General Ban Ki-moon warned in a report that South Sudan faced a very real risk of mass atrocities and that peacekeepers would not be able to stop such a bloodbath. <br/><br/>Returning from a visit to South Sudan, the UN's adviser on genocide prevention Adama Dieng told the council that he was dismayed by what he saw. Dieng urged the Security Council to impose an arms embargo to halt the devastating flow of weapons fuelling the war.<br/><br/>The world's youngest nation, South Sudan descended into war in December 2013, leaving tens of thousands dead and more than 2.5 million people displaced.