In a meeting with prime minister Manasseh Sogavare on Friday, premiers of the nine provinces and the mayor of the capital Honiara signed an agreement to pursue the introduction of a federal system of government.
The idea for a federal constitution and a new system of government has been supported by successive Solomon Islands governments for almost a decade now.
But Mr Sogavare's administration is the first to make its adoption a priority.
Speaking ahead of the Friday meeting the prime minister said he was duty-bound to consult the provincial premiers on how best to move forward together to complete the important task.
A final draft of the federal constitution is to be handed over to prime minister Sogavare in June.
His office said there is widespread public and bipartisan support for the proposed change.
The only reservation in the so called, "Honiara Communique", signed by the provincial premiers and the prime minister is a call for an amendment of section 61 of the draft federal constitution.
It is unclear what the amendment will be but the section itself is entitled "Restoration" and stipulates conditions for returning public and foreign-owned land to customary landowners.