FORMER US president Bill Clinton has arrived in Northern Ireland attend the funeral of Martin McGuinness in Derry today.

Mr Clinton arrived at Dublin Airport with his cavalcade immediately heading north.

The funeral mass will be held at St Columba’s Church at 2pm.

Alex Salmond, Scotland's former First Minister, will represent the SNP at the funeral. Earlier today, Arlene Foster, the leader of the DUP and the last First Minister at Stormont to serve with Mr McGuinness confirmed she too would attend.

Mr Salmond said: “As First Minister I worked closely with Martin McGuinness and Ian Paisley as they worked to build the credibility of their devolved administration in Nothern Ireland and thus consolidate the peace.

“There can be no greater contribution to public life, and I recognise that today.”

The Northern Ireland Secretary of State, James Brokenshire, will represent the UK government at Mr McGuinness' funeral.

Former US President Barack Obama has added his voice to tributes to the former Sinn Féin minister, saying his leadership was "instrumental" during the peace process.

In statement he said: "I send my condolences to the family and many friends of Martin McGuinness, a man who had the wisdom and courage to pursue peace.

"His leadership was instrumental in turning the page on a past of violence and conflict that he knew all too well.

"In our meetings I was also struck by his good humour and persistent belief in a better future for the people of Northern Ireland.

"May Martin rest in the peace that he pursued in life and may his example inspire others to follow a path of reconciliation."

Irish President Michael D Higgins will attend both the funeral of Mr McGuinness and another in Derry, that of 27-year-old footballer Ryan McBride, who died suddenly on Sunday.

The Irish Tricolour will fly at half mast at his official residence Áras an Uachtaráin as well as the Dáil as a mark of respect to Northern Ireland's former deputy first minister.

Mrs Foster, whose refusal to step down as First Minister over a botched green energy scheme, prompting a election this month, said: “It is precisely because of his past, because of his involvement with the IRA in the 70s and 80s, because of his influence within those circles that he was able to play the role he played in bringing the republican movement towards using peaceful and democratic means and because of all of that I doubt we will ever see his like again.”

Unionist leaders have acknowledged the important role Mr McGuinness played in the peace process, but also said his death on Tuesday was a difficult day for IRA victims.

But Jim Allister of the Traditional Unionist Voice said the former IRA commander's “hands drip with the blood of the innocent”.

Mr McGuinness is reported to have planned his funeral, with concerns it would be characterised by paramilitary trappings refuted.

He died in the early hours of Tuesday morning, surrounded by his family, after a short illness. He was 66.

Thousands of mourners are expected to attend the service, which takes place amid a huge security operation.