The Palestine Liberation Organisation says it will not be drawn into military action in a Palestinian refugee camp in Syria that has been overrun by fighters from the Islamic State in Iraq and the Levant (ISIL).
The statement late on Thursday contradicted assertions made earlier in the day by a PLO emissary to Damascus, Ahmad Majdalani.
He said that Palestinian groups are ready to join forces with the Syrian government to expel ISIL from the Yarmouk camp, the Associated Press news agency reported.
The PLO said it called for non-military means to "spare the blood of our people" and it refused "to be drawn into any armed campaign."
The statement came as Ban Ki-moon, UN secretary-general, called for action to prevent a massacre of Palestinian refugees in the camp.
"What is unfolding in Yarmouk is unacceptable," Ban said at the UN headquarters on Thursday. "We simply cannot stand by and watch a massacre unfold."
Ban described the situation as "the deepest circle of hell" in Syria's four-year civil war.
The International Committee of the Red Cross (ICRC) has joined a growing chorus of aid groups calling for immediate access to the camp.
ISIL seized much of the Yarmouk camp on the edge of Damascus last week, establishing a foothold in Damascus for the first time.
About 18,000 people are left in Yarmouk, following a two-year government siege.