Barack Obama has discussed Iran having a role in helping to stabilise Iraq - so long as it respects all sides. The UK Foreign Secretary William Hague has already spoken about talking to Iran.
But Mr Hague told ITV News today there would be no on-the ground sharing of British counter-terrorist expertise with Iranian officials.
ITV News Political Editor Tom Bradby spoke to Mr Hague:
David Cameron has said it's important he doesn't "pick Iraq's leaders" during a meeting with Nato's General Secretary Anders Fogh Rasmussen at Downing Street.
Mr Cameron told waiting journalists: "It's important that I don't pick Iraq's leaders, the people of Iraq pick their leaders, but what matters is that those leaders run that country on a non-sectarian basis, because running it on a more sectarian basis is part of the problem we are facing today."
The meeting took place as president Barack Obama prepared to announce that he is deploying about 100 Green Berets to Iraq to help train and advise Iraqi forces.
William Hague has told ITV News that under the current circumstances, the Government is "not planning, contemplating, or having meetings about Britain taking military action in Iraq."
He said that moves are being made to try to persuade Iraqi leaders to work together, provide aid and expertise, but "none of that means British soldiers going to Iraq".
Foreign Secretary William Hague has told ITV News Political Editor Tom Bradby that Iraq faces a "severe challenge to its existence as a state" and the current conflict will be a "decisive moment in its history."
Foreign Secretary William Hague has told ITV News Political Editor Tom Bradby that Iraq faces a "severe challenge to its existence as a state".
William Hague tells ITV News Iraq faces a severe challenge 'including to its existence as a state.'
But he completely rules out military intervention; 'we are not planning that, we're not contemplating that, we are not having meetings...'
The UK Foreign Secretary William Hague rejected a claim the government was "softening" its approach to Iran.
Speaking in the parliament, Mr Hague described the UK as "absolutely relentless" in its efforts to defeat terrorism around the world and added: "I can assure you that there is no softening of any of our policies in relation to Iran.
William Hague might have announced the reopening of the British embassy in Tehran today, but the Foreign Office is still advising people against traveling to the Middle Eastern country.
The Foreign Office currently advises "against all but essential travel" to most of the country, and "against all travel" to the eastern parts of Iran near the borders with Afghanistan and Pakistan.
People planning to travel to Iran should check the Foreign Office travel advice regularly and sign up for email alerts on the security situation, the spokesperson said.
The Secretary of State William Hague has issued a statement on the possible reopening of the British embassy in the Iranian capital, Tehran:
Our two primary concerns when considering whether to reopen our embassy in Tehran have been assurance that our staff would be safe and secure, and confidence that they would be able to carry out their functions without hindrance.
There are a range of practical issues that we will need to resolve first.
However it is our intention to reopen the Embassy in Tehran with a small initial presence as soon as these practical arrangements have been made.
William Hague has announced that Britain wants to reopen the British embassy in Iran as the West looks to normalise relations to help ease the crisis in neighbouring Iraq.
The Foreign Secretary told MPs that "circumstances are right" to re-open the British embassy in Tehran.
Mr Hague said he had discussed a number of matters in a meeting yesterday, including the situation in Iraq, with Iranian counterpart Mohammad Javad Zarif.
The UK has had no diplomatic presence in Tehran since a mob ransacked the British embassy in 2011.