Tony Blair has apologised for mistakes during the Iraq War - and said there were "elements of truth" to claims it caused the rise of Islamic State.
The ex-PM said "those of us who removed Saddam" did bear some responsibility for the situation in Iraq today.
But he again defended the invasion, saying it was "hard to apologise" for removing Saddam Hussein and that Iraq might have become like Syria otherwise.
Scottish First Minister Nicola Sturgeon said it was a "Blair spin operation".
Mr Blair's comments come shortly before Sir John Chilcot announces a timetable for completion of his inquiry into the war.
The Mail on Sunday described the interview as an "astonishing" apology, but a spokesman for the former prime minister said there was nothing new in his words.
BBC political correspondent Iain Watson said any apologies from Mr Blair were strictly limited.
In an interview - which is yet to be broadcast - with US news channel CNN, Mr Blair said even if his policy in Iraq did not work, subsequent policies had worked no better.
He believed it was better that Saddam Hussein was no longer in power and suggested that if the Iraq invasion had not taken place there was a danger the country would have degenerated into civil war, as Syria did.
He said: "I apologise for the fact that the intelligence we received was wrong.
"I also apologise for some of the mistakes in planning and, certainly, our mistake in our understanding of what would happen once you removed the regime."
Mr Blair has made apologies on both of these points before, to Parliament and to the Iraq Inquiry.
But he told CNN: "It is when - as I say - am asked to go further and say, well in that case we would be better off as a world if he was still there, and that is really where I have to part company with people."
Asked if the war was the "principle cause" of the rise of the Islamic State (IS or ISIS) militant group, he replied: "I think there are elements of truth in that.
"Of course you can't say those of us who removed Saddam in 2003 bear no responsibility for the situation in 2015, but it is important to also realise that the Arab Spring which began in 2011 would have also had its impact on Iraq today."
He also pointed out that IS had come to prominence in Syria - not in Iraq.
Sir John Chilcot's long-awaited report into the Iraq War is now reaching a conclusion, although no date has yet been given for its release - more than six years after the inquiry was set up by then prime minister Gordon Brown with an assurance it would take a year.
Ms Sturgeon tweeted: "The Blair spin operation begins but the country still awaits the truth. The delay to Chilcot report is a scandal."
But Mr Blair's office denied the interview was an attempt to set out his version of events before facing probable criticism.
A spokesman said: "Tony Blair has always apologised for the intelligence being wrong and for mistakes in planning. He has always also said and says again here that he does not however think it was wrong to remove Saddam.
"He did not say the decision to remove Saddam in 2003 'caused Isis' and pointed out that Isis was barely heard of at the end of 2008, when al Qaeda was basically beaten.
"He went on to say in 2009, Iraq was relatively more stable. What then happened was a combination of two things: there was a sectarian policy pursued by the government of Iraq, which were mistaken policies.
"But also when the Arab Spring began, Isis moved from Iraq into Syria, built themselves from Syria and then came back into Iraq. All of this he has said before."