The centenary of Northern Ireland’s foundation next year is a cause for celebration, the Prime Minister said.

Boris Johnson envisaged marking the UK’s “extraordinary” achievements around the world as he announced the first steps during a visit to Belfast.

He acknowledged Irish nationalists, who have highlighted past religious discrimination, may not share his view and said learning other perspectives could be incredibly valuable.

“I think it’s very important that we should commemorate and look at the importance of this.

“From my point of view it is something obviously to celebrate, because I love and believe in the union that makes up the United Kingdom, the most successful political partnership anywhere in the world.

“But of course I appreciate there will be plenty of people who take a different point of view.”

The Prime Minister has outlined plans to establish a centenary forum and a centenary historical advisory panel to mark 100 years since the foundation of Northern Ireland and today’s UK.

Leaders of Stormont’s powersharing administration immediately differed over the prospect.

Republicans will not honour the creation of a state built on religious discrimination, Sinn Fein’s deputy first minister Michelle O’Neill said.

DUP leader and First Minister Arlene Foster said events next year could be held in an inclusive fashion which did not cause offence and recalled previous contentious anniversaries in the republican calendar.

Mrs O’Neill said: “When it comes to partition Northern Ireland was built on sectarianism, gerrymandering (tampering with voting districts to deliver certain results) and an inbuilt unionist majority and that is not something that I would ever celebrate.”

Sinn Fein’s vice-president said it was important that republicans engaged in the debate around partition and looked to the future.

“There is no doubt in most people’s minds that partition has failed everyone, our people, our economy, our two islands,” she said.

Northern Ireland was created in May 1921 following the partition of Ireland.

Mrs Foster said: “I think it is an event for the whole of Northern Ireland, looking forward to the future, looking forward to our young people having a place in the world and that is what I want to see happening for our centenary plans.”

She added: “It is important that we recognise the reality that Northern Ireland is part of the UK and has been for 100 years.

“We also recognise that there have been a number of anniversaries already passed by.”

Those include the centenary of the 1916 Easter Rising against British rule and First World War dates like the Battle of the Somme in which many Ulster soldiers died.

Mrs Foster added: “It is important that we mark these next year centenary events in a way that does not cause offence and in a way that is inclusive.”

The new Northern Ireland state, comprising six northern counties, had a unionist majority and went on to play a significant part in British industry and war efforts.

Irish republicans committed to a united Ireland criticised what they felt was an inequitable distribution of political and economic power north of the border.

The civil rights movement of the 1960s highlighted demands for rights like one man one vote and reform of public housing allocation.

As IRA and loyalist violence ramped up, Westminster imposed direct rule from London early in the Troubles.

Taoiseach Micheal Martin said it was important that the centenary events were respectful and enlightening.

“History for me is about enlightening the generations to come and current generations,” he said.

“It’s not about trying to prove a point – there will be different perspectives in relation to obviously the centenary commemoration of 1920 and 1921 in respect of the island of Ireland, both in the Republic we will be doing our centenaries and likewise in the north.”