Somalia is seen as a potential new base for al-Qaeda
Somalia has been without a recognised central government since 1991, and recent attempts to establish a new authority, based in the capital Mogadishu, have had mixed results.
The seven Igad states have long been divided on the best way forward for Somalia, especially as the current transitional government blames fellow Igad member Ethiopia for sabotaging the peace process by supporting hostile warlords.
But the BBC's Richard Lee in Khartoum says the decision to hold the meeting is a step forward, although there is no guarantee that all the key players will in fact turn up.
Elusive details
Earlier, the summit also agreed to a resolution to continue with efforts to bring peace to Sudan, and delegated Kenyan President Daniel arap Moi to coordinate the various different initiatives.
They also adopted a resolution condemning international terrorism and called for joint action to combat it throughout the region.
But differences between the countries, in particular over the definition of terrorism, ensured that the proposal did not include any actual concrete policies.
Sudan and Somalia have been mooted as possible targets in any second phase of the US-led war against terrorism.
Osama Bin Laden's al-Qaeda network, blamed for the 11 September attacks on New York and Washington, is thought to have cells in Sudan and Somalia, and Sudan is still on the US list of state sponsors of terrorism.
Somalia looks an increasingly likely candidate for the much-discussed next phase of the war, but the other conference members have reason to be wary too.
Eritrea, Kenya, Uganda and Ethiopia have all been named by Washington as housing al-Qaeda cells.
The region remains attractive to terrorist groups because large swathes of it are beyond central government control.
Igad was originally set up to deal with drought in East Africa and the seven leaders also look at development issues.