Martin McGuinness mulls his Sinn Féin future but has 'energy of a 20-year-old'
Martin McGuinness has said Sinn Féin is looking seriously at transition in its leadership, but he has not yet decided if May's election will be his last.
Now aged 65, Mr McGuinness will be 70 by the time the next Northern Ireland Assembly term is due to conclude.
However, he said he still has the "energy of a 20-year-old" and that very few people could "keep up" with him.
He said he recognises that no one goes on forever, but added his age is less important than his energy and health.
Mr McGuinness, who has held the post of Northern Ireland deputy first minister since 2007, made his remarks on BBC Radio Ulster's Inside Politics programme.
Both the Democratic Unionist Party (DUP) and the Social Democratic and Labour Party (SDLP) will contest this year's Northern Ireland Assembly elections with newly-appointed leaders.
Speaking about his own party, Mr McGuinness said: "I think Sinn Féin always has to look at the whole issue of transition and we are looking seriously at that, but I have the energy of a 20-year-old, there's not too many people that can actually keep up with me."
When he was asked about the possibility of him standing for political office again in 2021, Mr McGuinness did not rule it out.
"That would be something that I would have to seriously consider at that stage, but I certainly intend to lead Sinn Féin into this election," he said.
'Joint first ministers'
He also told Inside Politics that his party will mark the centenary of the Battle of the Somme later this year in an appropriate and respectful manner.
He said he regarded this as a priority in the current year of significant anniversaries.
He predicted that Sinn Féin would get a "substantially increased mandate" south of the Irish border after the forthcoming general election in the Republic of Ireland.
He said he believes there is a "strong possibility" that Sinn Féin will be in government in Dublin by the summer.
Mr McGuinness reiterated that if Sinn Féin emerges from the Northern Ireland assembly elections in May as the largest single party, he will immediately offer to change the title of the top two jobs at Stormont to "joint first ministers" of Northern Ireland.
Inside Politics will be broadcast on BBC Radio Ulster at 18:05 GMT on Friday 15 January and will be repeated at 13:35 GMT on Sunday 16 January.