"Assuming the great responsibility imposed by the great challenges facing our Arab nation and threatening its capabilities, the Arab leaders had decided to agree on the principle of a joint Arab military force," Egyptian President Abdel Fattah al-Sisi told the summit in the resort town of Sharm el-Sheikh. The decision was mostly aimed at fighting jihadists who have overrun swathes of Iraq and Syria and secured a foothold in Libya, Arab League chief Nabil al-Arabi said ahead of the summit.
On Sunday, Arabi told the meeting the region was threatened by a "destructive" force that threatened "ethnic and religious diversity", in an apparent reference to the Islamic State group.
"What is important is that today there is an important decision, in light of the tumult afflicting the Arab world," he said.
Egypt had pushed for the creation of the rapid response force to fight militants, and the matter gained urgency this week after Saudi Arabia and Arab allies launched air strikes on Huthi rebels in Yemen.
Arabi, reading a statement at the conclusion of the summit, said on Sunday the offensive would continue until the Huthis withdraw from regions they have overrun and surrender their weapons.
Several Arab states including Egypt are taking part in the military campaign, which Saudi King Salman said on Saturday would continue until the Yemeni people "enjoy security". Yemeni President Abedrabbo Mansour Hadi at the start of the summit called for the offensive to end only when the Huthis "surrender", calling the rebel leader an Iranian "puppet".
However, UN Secretary-General Ban Ki-moon urged the leaders to find a peaceful resolution in Yemen.