First Minister Jack McConnell has insisted he would serve a full four-year term if Labour wins next May's Holyrood elections.
Mr McConnell is Scotland's longest serving first minister
Mr McConnell's comments came as he celebrated the fifth anniversary of becoming first minister.
At the weekend, Mr McConnell said there had been moments in that time when he questioned the impact the job was having on his personal life.
He has now said he wants to continue in the post as there is "more to be done".
Mr McConnell, who took over the top job in Scotland's devolved executive when Henry McLeish resigned, insisted he was in "no doubt" that the country was in a better position than five years ago.
"Our economy is stronger, there are more jobs, better public services, and the quality of life is improving," he said.
Mr McConnell told BBC Newsnight Scotland: "On the issue of the third term in the parliament - I want to be first minister for that third term of the parliament.
"I am absolutely clear that my ambitions for Scotland in the third term of the Scottish Parliament - developing the education system to be amongst the very best in the world again.
"To, for example, win the Commonwealth games for Glasgow and all these other ambitions that we have for that time, require a full term."
However, he also warned his party that the SNP could win the election.
He said the Nationalists were not taken seriously in 2003.
"They were actually at one point neck and neck with us in the polls," he said.
"But nobody thought they would win."
Mr McConnell added: "Now six months out, there is a real possibility that the Nationalists could win in May and could take Scotland to the brink of independence."
He said the choice was between "a better Scotland with our own decisions being made inside the UK" or going down a path of separating Scotland from its main economic market and other ties to the UK.
The first minister, who has served twice as long as his two predecessors managed, said the devolution train had almost come off the rails during the "very turbulent" two and a half years before he took over.
He said: "There was a big question mark over whether it was possible to have the leadership that was required in the parliament from the executive, that the parliament itself could find a way of functioning effectively, questioning the executive, passing good legislation.
"Out there, I think, people were questioning whether we would ever do anything that really directly affected their lives"
In 2002 there had had been a real danger that the election turnout could fall to 40% or lower, said Mr McConnell.
"As I said then there are credibility problems if interest falls to that level," said Mr McConnell.
"So I thought it was really really important to get the basics right, to get some basic organisation and discipline into the organisation but also to focus on the issues that really matter."
SNP Holyrood leader Nicola Sturgeon said Mr McConnell had offered "weak leadership, prevarication and broken promises".
She said it was up to the people of Scotland to decide if Mr McConnell remained in his job.
Ms Sturgeon attacked him over issues ranging from the Trident missile replacement to new nuclear power stations, council tax levels, hospital closures and youth offending.
"He's too often a rabbit caught in the headlights on the big issues of the day, rather than the real leader Scotland needs," she said.
"This week Mr McConnell has finally caught up with public opinion in Scotland, and started to question his own effectiveness and lack of achievement.
"If he has a lack of confidence in his own ability, it's not credible to think that others will still think him the best person for the job."
The Conservatives said it was an "unhappy anniversary" marking half a decade of "centralised, nanny state government and missed opportunities".
They attacked Mr McConnell over law and order, rising numbers of children in care, hospital waiting times and council tax rises.
Scottish Conservative leader Annabel Goldie said: "There is a continued strong desire for devolution to deliver and a growing frustration that the Labour-Lib Dem Executive, led by Jack McConnell, is squandering the chance."