LONDON - Former British prime minister Tony Blair has apologised for “mistakes” made in the US-led invasion of Iraq in 2003.

Blair also said there are “elements of truth” in claims that the invasion was the main cause of the rise of the Islamic State group.

Blair’s decision to send troops to back the US-led invasion is still a live political issue in Britain, where a six-year public inquiry into the conflict is yet to publish its findings.

Asked whether the offensive was the principal cause of the rise of Islamic State, which now controls large areas of Iraq and neighbouring Syria, Blair said there were “elements of truth” in that. “Of course, you can’t say that those of us who removed (former Iraqi dictator) Saddam (Hussein) in 2003 bear no responsibility for the situation in 2015,” Blair told CNN in an interview broadcast on Sunday.

Critics say the US decision to disband Saddam Hussein’s army after the invasion created a huge security vacuum exploited by Al-Qaeda, which was eventually replaced by Islamic State.

Some former Iraqi army officers, members of the Sunni minority which says it has been marginalised by the Shi’ite-led government backed by Western powers, are senior strategists in Islamic State. The Iraqi government says it has not marginalised Sunnis.

Blair said the “Arab Spring” uprisings across the region also affected Iraq, and pointed out that Islamic State had risen out of a base in Syria, not Iraq.

Blair apologised for what he described as mistakes in planning and intelligence before the war and in preparations for what would happen once Saddam was removed, but said it had been the right decision.

“We have tried intervention and putting down troops in Iraq; we’ve tried intervention without putting in troops in Libya; and we’ve tried no intervention at all but demanding regime change in Syria. It’s not clear to me that, even if our policy did not work, subsequent policies have worked better,” he said.

“I find it hard to apologise for removing Saddam. I think, even from today in 2015, it is better that he’s not there than that he is there.”

By the time the war officially ended on Dec. 15, 2011, more than 4,000 US troops and 179 British servicemembers had died and over 100,000 Iraqi civilians were killed, according to the website Iraq Body Count.

More than 3,000 American soldiers are currently in Iraq, training and advising government forces and police.

The comments from Blair, a divisive figure for leading Britain into the Iraq war, come shortly before a timetable for the publication of the much-delayed public inquiry into the Iraq war is due to be announced.

Amid intense pressure to publish from lawmaers and families of military personnel killed in the war, John Chilcot will write to Prime Minister David Cameron by November 3 saying when the inquiry, launched in 2009, will be completed.