US President Barack Obama said on Monday that the \"killing of innocents\" must end in Sudan and South Sudan, after weeks of border fighting in contested regions and tension between the two states. \"In Darfur, Abyei, South Kordofan and the Blue Nile, the killing of innocents must come to an end. The presidents of Sudan and South Sudan must have the courage to negotiate because the people of Sudan and South Sudan deserve peace,\" Obama said at the US Holocaust Museum in Washington.