Tunisia's president has said he will not seek a new term in office in 2014, following widespread protests which have left at least 23 people dead.
Zine al-Abidine Ben Ali said he was also ordering police to stop using live rounds, hours after at least one person was shot dead in the capital Tunis.
Human rights groups say more than 60 people have died in weeks of unrest across the country.
Mr Ben Ali, 74, has ruled the country virtually unchallenged since 1987.
Speaking in his third nationally-televised address since the violence began, he said there was "no presidency for life" in Tunisia.
Many had expected him to amend the constitution to remove the upper age limit for presidential candidates and enable him to stand again in 2014, but he said he did not intend to do so.
The president, who earlier this week blamed the unrest on "terrorists", said he felt "very, very deep and massive regret" over the deaths of civilians in recent weeks.
He said he had ordered troops to stop firing on protesters except in self defence, saying: "I won't accept that another drop of blood of a Tunisian be spilled".
The speech also addressed other key concerns of the protesters, pledging "total freedom of the press and a removal of internet restrictions" and promising to take action on food prices, which have gone up fourfold in recent weeks.
The US, the EU and the UN have all criticised the government's response to the unrest and called on the security forces to show restraint.
The UK has advised against all non-essential travel to Tunisia while the protests continue.
The US has issued a similar warning, citing "intensifying political and social unrest in Tunisia".
Trade unions have called on people to observe a general strike on Friday in the capital and other areas. BBC News
