The heads of Arab League countries meeting in Egypt have agreed to create a joint Arab military force.
The League has been meeting in Sharm el-Sheikh amid a crisis in Yemen and the threat of jihadists who have made major gains in Iraq, Syria and Libya.
However, establishing the make-up and remit of the force could take months, analysts say.
A 10-nation, Saudi-led coalition is currently carrying out air strikes against rebels in Yemen.
The strikes are in support of President Abdrabbuh Mansour Hadi, who fled after gains by the Shia Houthi rebels.
Correspondents have described the conflict as a proxy war between Sunni Arab nations and Shia Iran.
Egyptian President Abdel Fattah al-Sisi said: “The Arab leaders have decided to agree on the principle of a joint Arab military force.”
Analysis: Alan Johnston, BBC Middle East analyst
Like everyone else, President Sisi sees plenty to worry about as he looks across the Middle East. He describes the growing threats to the region as “unprecedented”.
Unsurprisingly this military man loudly advocates military solutions. And now he has got agreement on the principle of establishing a joint Arab military force.
We are yet to see what this might look like in detail. And there will be plenty of sceptics.
In an area as sensitive as military intervention, how much real coordination might be possible across an Arab world that is so often so easily divided?
But perhaps things are changing a little. Even as President Sisi spoke, exactly the kind of action he wants to see was unfolding. A Saudi-led joint Arab force – which has come together surprisingly quickly and easily – was striking at Houthi rebel targets in Yemen.
The Arab League will work with military representatives of its members to organise what has been described as a voluntary force.
Analysts say it is unlikely all 22 members will join the proposed force.
Egyptian officials quoted by Associated Press said the force would comprise some 40,000 elite troops, supported by war planes, naval vessels and light armour.
The creation of the joint force has long been floated within the League but has never been realised.
There has been no indication such a force would de deployed in the Yemen conflict.
However, Arab League chief Nabil al-Arabi said the Saudi-led offensive against the Houthis would “continue until the militia withdraws and surrenders its weapons”.
He added: “Yemen was on the brink of the abyss, requiring effective Arab and international moves after all means of reaching a peaceful resolution have been exhausted to end the Houthi coup and restore legitimacy.”
Saudi Arabia says the Houthis are backed by regional rival Iran – something the rebels deny.
Mr Hadi on Saturday accused Tehran of destabilising the country, calling the Houthis the “stooges of Iran”.
The Houthis have said their aim is to replace Mr Hadi’s government, which they accuse of being corrupt.