The Prime Minister has promised the UK will do "everything [it] can" to stop people travelling to Iraq to join Islamic State fighters.
Speaking in No. 10, David Cameron told his Iraqi counterpart Haider al-Abadi:
The threat from extremist terror you face in Iraq is also a threat we face here in the United Kingdom.
We will do everything we can to help stop foreign fighters coming to your country and creating the mayhem we see today.
Islamic State militants could begin orchestrating terror attacks on the UK and other Western countries from their base in Syria unless urgent action is taken, the Foreign Secretary has warned.
Speaking to ITV's Good Morning Britain, Philip Hammond said the biggest threat to security currently was the potential for "lone wolf" attacks inspired by jihadist activities overseas.
But if extremists managed to keep hold of their territory in the Middle East, he warned, the UK could expect to see organised attacks being planned and executed from afar.
It comes as a meeting is set to be held at Lancaster House in London to discuss the global response to the terrorist group.
Islamic State militants seeking to "subvert and destroy the values of democracy" must be defeated, the Foreign Secretary has warned - saying action was crucial "for the security of Britain."
Foreign ministers from around the world were due to fly in to London today for a top-level summit discussing how to take the terror group down.
US secretary of state John Kerry, Iraqi prime minister Haider al-Abadi and French foreign minister Laurent Fabius will be among leaders from 21 countries joining the talks.
They will focus not only on military support for opposition fighters but ways to cut off Islamic State finances, stop its influence spreading and preventing foreign fighters joining their ranks.
In an article for the Daily Telegraph, Philip Hammond said:
Some say that Britain should leave this fight to others. But we cannot sub-contract the safeguarding of our nation's security.
Nor can we ignore an organisation that seeks to subvert and destroy the values of democracy, free speech, freedom of religion and the rule of law that are so fundamental to our way of life.
The families of the 179 British troops who lost their lives in the Iraq war have found delays to the Chilcott Inquiry report deeply distressing.
ITV News correspondent Dan Rivers spoke to Reg Keys, who lost his son Tom during the conflict, about his wait for answers:
Roger Bacon, who lost his son Matthew in 2005 during the Iraq conflict, said he is desperate for answers about why the UK went to war.Read the full story ›
Political leaders and the parents of the casualties of the 2003 war have been united in their anger and frustration at further delays to the publication of the Chilcot Iraq War report.
The report is apparently being held up because not everyone implicated in it has had their right to reply but Former Prime Minister Tony Blair, who backed George W Bush and took Britain to war, insisted the delay was not because of him.
ITV News' Political Editor Tom Bradby reports:
A spokeswoman for the Iraq War inquiry has confirmed that Sir John Chilcot received the invitation to appear before the Foreign Affairs Select Committee and was considering his response.
Chairman of the Committee, Sir Richard Ottaway, has written to Sir John asking him to face MPs "at some point in the next two weeks" to explain "what stage preparation of the report has reached and what obstacles remain" before it can be submitted.
The father of a soldier killed in Iraq has told ITV News he is "absolutely disgusted" by the latest delay in publishing the inquiry report into the war.
Roger Bacon, whose son, Major Matthew Bacon, was killed in Basra in 2005, said the families of fallen servicemen needed answers from Sir John Chilcot's panel.
"I'm absolutely disgusted by it. By the time this inquiry is published, it will probably have taken longer than the whole of the Iraq war - that's absolutely ridiculous," Mr Bacon told Mary Nightingale.
Delays to the publication of the Chilcot Inquiry are not down to senior politicians trying to "dodge" criticism, David Cameron has said amid growing anger.
The Prime Minister said there was "no mystery" behind Sir John Chilcot's announcement that his panel's findings would not be published before May's general election.
"My understanding is that there is no mystery in why this is taking so long," Mr Cameron said.
"It is a very thorough report and you have to give the people who are criticised in a report the opportunity to respond to all those criticisms.
"That is what is happening at the moment. I don't believe, from what I understand, that anyone is trying to dodge this report or put off this report."
Tony Blair has denied suggestions that he has caused the delay in the publication of the Chilcot report.
A spokesperson for Mr Blair said the former prime minister "regrets" the delay and wanted the inquiry to be allowed to proceed with its work.
We have repeatedly said that it is not true to say that Tony Blair has caused the delay in the report’s publication.
Sir John’s letter makes reference to notes and records concerning Mr Blair, which some may interpret as an implicit suggestion that Mr Blair caused the delay, this is not true.
On the contrary, he regrets this delay in its publication.
Incorrect allegations and politically motivated speculation do nothing to shine a light on the issues involved.
It is an independent inquiry and it should be allowed to proceed with its work.