The Sinn Fein member was in Helsinki, Finland, for a four-day visit which ended yesterday, alongside South African mediator Cyril Ramaphosa.

They met Iraqi parliamentarians to address violence which has killed thousands.

A spokesman for the Sinn Fein minister said: "It was a follow-up to the earlier meeting. He chaired the meeting alongside Mr. Ramaphosa."

Along with the ex-president of Finland, Martti Ahtisaari, Mr. Ramaphosa was appointed an inspector of the IRA weapons dumps in Northern Ireland. He was a senior ANC member in South Africa.

Last year Mr McGuinness led politicians including Northern Ireland Lagan Valley MP Jeffrey Donaldson in negotiations in Helsinki which produced a series of non-violence principles to bring Sunni and Shia Iraqi politicians together.

Other members of the talks team included the SDLP's Sean Farren, Mr Donaldson, now a DUP Junior Minister at the Office of the First and Deputy First Minister, Alex Maskey of Sinn Fein and former loyalist Belfast leader Billy Hutchinson.