Arab League chief Nabil al-Arabi on Sunday called for a military and political confrontation with Islamic State jihadists and other militants he said threatened the existence of Arab states.
Arabi's remarks, at a meeting of Arab foreign ministers, came as the United States expanded air strikes against the militants in Iraq and sought wider regional backing for its campaign.
"What is needed is a clear decision for a comprehensive confrontation, militarily and politically," Arabi said a day after he and US Secretary of State John Kerry discussed taking action against the jihadist group that controls parts of Syria and Iraq.
An Arab League diplomat told reporters that the ministers were considering adopting a resolution on combating IS and "coordinating with the United States to confront this terrorist organisation".
Arabi criticised infighting between Arab states which he said had led to inaction by the 22-member bloc.
"While some (Arab) states object to allowing the Arab League to intervene in their internal crises, the floodgates are opened to foreign intervention, including militarily," he said.
Arabi, a former foreign minister of Egypt, called for the activation of an Arab defence treaty to allow for military action when needed.
Iraq earlier welcomed US President Barack Obama's plan for an international coalition against jihadists as a "strong message of support", after repeatedly calling for aid against the militants.
Obama outlined the plan at a NATO summit Friday for a broad coalition to defeat IS, which led an offensive that overran parts of Iraq in June and also holds significant territory in neighbouring Syria.
Obama's IS 'game plan'
He said Sunday he will make a speech Wednesday to lay out his "game plan" to deal with and ultimately defeat IS, but warned he would not wage another ground war in Iraq.
IS, originally an Al-Qaeda affiliate in Iraq that expanded in the Syrian conflict, claims its chief Abu Bakr al-Baghdadi is the rightful leader, or Caliph, of all Muslims.
The group's astonishing rise in Syria and Iraq caught the weak government in Baghdad, and much of the region, off guard.
Arabi said IS posed a threat to the entire region.
"What is happening in Iraq is that the terrorist organisation not only threatens a state's authority, but threatens its very existence and the existence of other states," he said.
Arab countries have participated in Western-led military campaigns in the past, including the first Gulf War and the aerial campaign against former Libyan dictator Moamer Kadhafi.
The United States on Sunday expanded its month-long air campaign against the militants in Iraq's Sunni Arab heartland, hitting IS fighters west Baghdad as Iraq troops launched a ground assault.
Aside from fighting in Iraq, Arab states are concerned that IS is coordinating with domestic extremists and that militants who travelled to join the group may conduct attacks on their return home.
In Egypt, several militants who have carried out attacks on security forces since the army overthrew Islamist president Mohamed Morsi in 2013 had travelled to fight in Syria.
Egypt's main militant group, Ansar Beit al-Maqdis, has not publicly pledged its loyalty to IS, but has referred to the jihadists as "brothers".