The Somali president and prime minister will hold face-to-talks in Ethiopia in an attempt to resolve an ongoing rift between the two leaders.
Relations between President Abdullahi Yusuf and Premier Hussein Nur Adde have been strained in the past few weeks.
There are fears that the rift could affect a ceasefire agreement signed with the opposition in June.
Meanwhile, there have been two blasts along the road to the Mogadishu airport as the two leaders left for Ethiopia.
Reports say the insurgents detonated two landmines near the convoy, and that Ethiopian-backed government troops responded by opening fire, killing five civilians.
Ethiopia helped government forces oust the Islamists in 2006 but has since become bogged down in Somalia.
The BBC’s Elizabeth Blunt in Addis Ababa says Ethiopia is growing increasingly impatient with the constant feuding within the Somali government’s ranks.
The rift between the two leaders has spread to parliament, where supporters of President Yusuf have threatened to pass a vote of no confidence in the prime minister.
Mr Nur Adde and top Islamist leader Sheikh Sharif Sheikh Ahmed signed a three-month ceasefire agreement in June.
Delegations from both sides are to consider political and security issues at a meeting in Djibouti on Saturday.
Another prominent Islamist leader, Sheikh Hassan Dahir Aweys, has refused to negotiate until all Ethiopian troops had left the country
Our correspondent says Ethiopia should have some influence over President Yusuf as his government would be extremely vulnerable without Ethiopian military support.
Former Prime Minister Ali Mohamed Ghedi was forced out of government in October after a series of disagreements with President Yusuf.
When Mr Nur Adde replaced Mr Ghedi, he was seen as a neutral figure who would make competent prime minister.
Somalia has experienced almost constant civil conflict since the collapse of Mohamed Siad Barre’s regime in January 1991.