Political analyst Dr. Claire Rice said it was crucial for Northern Ireland to bring back the British region's devolved government. "It's extremely significant, important that this day is happening at all. We've had public sector strikes, we have a health care service in crisis, we have education, infrastructure, everything really is starting to struggle at this stage. And in the absence of leadership, things have only been getting worse," she said.

Rice said the nationalists' new leadership position could give them "an enhanced platform to be able to project Sinn Fein's interests on the ideas around Irish unification", but pointed out their power is limited by Northern Ireland's government structure. "We've got a power sharing system here for a good reason and that's the way things have to work here," she added.

Sinn Fein is the former political wing of the Irish Republican Army (IRA), in both Northern Ireland and the Republic of Ireland, long shunned by the political establishment on both sides of the border. It is now the most popular party on both sides.

The post of deputy First Minister, which has equal power but less symbolic weight, was taken by the DUP's Emma Little-Pengelly.