The UN Security Council has defeated a US-sponsored resolution that would have imposed an arms embargo on South Sudan and three key figures in the conflict in the world's newest nation.<br/><br/>Seven council members voted today in favour of the resolution and eight abstained.To be adopted by the UN's most powerful body a resolution needs nine "yes" votes.<br/><br/>UN Secretary-General Ban Ki-moon has repeatedly called for an arms embargo, warning that "If no action is taken, South Sudan will be on a trajectory towards mass atrocities."<br/>