South Sudan sees northern border zone within a month JUBA (Reuters) - South Sudan hopes to establish a demilitarized zone along its border with arch-rival Sudan within a month, paving the way for vital oil exports to resume, a southern official said on Monday. Sudan leader Omar Hassan al-Bashir and South Sudan's Salva Kiir met in Ethiopia at the weekend to try to quell tensions that have rumbled since a flare-up of violence along the disputed border in April last year, the worst since the South seceded in 2011. South Sudan became independent in July 2011 under a 2005 peace agreement which ended decades of civil war but the neighbors have yet to resolve a long list of disputes. The southern government in Juba shut down its entire oil output of 350,000 barrels per day (bpd) a year ago after failing to agree on an export fee with the north. It had hoped to be producing 230,000 bpd by December after agreeing in September to set up a buffer zone along the 2,000 kilometer (1,200 miles) border. But neither side has withdrawn its army from the frontier. Both economies desperately need the oil to flow again from the fields in South Sudan through the north to a Red Sea terminal and onward to foreign markets. South Sudan's chief negotiator Pagan Amum said Juba and Khartoum had agreed to start establishing the buffer zone and another round of talks was set for Saturday in the Ethiopian capital Addis Ababa. "So I am very hopeful that the border implementation will be completed within the next 20 to 30 days," Amum told reporters in the southern capital. He said Ethiopian monitors supposed to patrol the border with soldiers from both sides were waiting to be deployed after finishing their training. South Sudan's oil minister said last week that crude would need two months to reach the Red Sea terminal after production resumes, suggesting oil exports could hit markets by mid-April if the buffer zone is operational by mid-February. Amum blamed Sudan for the delay in securing the border and said Khartoum might decide to block the plan by making new demands. Sudan denies it is responsible for the delay. "We will be waiting to see on the 13th ... whether they will now allow the oil to flow and the other agreements implemented or they will come up with new conditionalities as usual," he said. Diplomats say the plan is complicated by the presence north of the border of the rebel Sudan People's Liberation Movement-North (SPLM-North), which wants to topple Bashir. Khartoum say Juba supports the SPLM-North. Juba denies that and says Sudan is backing militias on its territory. Writing by Ulf Laessing; Editing by Tom Pfeiffer