South Sudan’s warring sides have missed a deadline to form a unity government despite growing international condemnation of the conflict in the country.

Under the Cessation of Hostilities Treaty signed on May 9, President Salva Kiir and his former deputy Riek Machar had agreed to establish a unity government by August 10.

The latest round of peace talks between the two sides resumed last Monday in the Ethiopian capital Addis Ababa, but the delegates failed to meet for the rest of the week.

On Friday, the United Nations Security Council threatened to impose sanctions on both sides for their failure to resolve the ongoing conflict in the country.

The actions of the warring leaders “in continuing to pursue a military solution to this conflict are unacceptable,” according to a UN Security Council statement.

South Sudan plunged into violence in December 2013, when fighting erupted between troops loyal to the president and defectors led by Machar around the capital Juba.

The conflict soon turned into an all-out war between the army and defectors, with the violence taking on an ethnic dimension that pitted the president’s Dinka tribe against Machar’s Nuer ethnic group.

The clashes left thousands of South Sudanese dead and forced around 1.5 million people to flee homes in the world’s youngest nation.

The widespread displacement has contributed to mass hunger and food shortages. Aid workers warn of famine if fighting continues.

South Sudan gained independence in July 2011 after its people overwhelmingly voted in a referendum for a split from Sudan.