British SAS soldiers have been deployed to northern Iraq to "gather intelligence" ahead of any potential rescue operation, led by the US, to airlift thousands of Yazidi refugees from Mount Sinjar.

In the most dramatic sign of Britain's growing involvement in the Iraqi crisis, the SAS soldiers have moved to the region near Mount Sinjar where US special forces are coordinating the rescue effort.

Last night, a small team from the US landed on Mount Sinjar to assess the situation, and said that an evacuation mission was less likely as "there are far fewer Yazidis on Mount Sinjar than previously feared", according to Pentagon press secretary Rear Admiral John Kirby.

The deployment of British special forces emerged as Britain announced that it will fly Soviet-era ammunition from eastern European countries to Kurdish forces fighting jihadists from the Islamic State (Isis) in northern Iraq. The Elysée Palace went a step further as it indicated France may be prepared to arm the Kurds itself. As the EU and the US distanced themselves from the Iraqi prime minister, Nouri al-Maliki, by endorsing his proposed successor Haider al-Abadi, the EU's foreign policy chief Lady Ashton announced that an emergency meeting of foreign ministers would be held in Brussels on Friday to coordinate the EU's response.

The foreign ministers are expected to give the green light to arming Kurdish refugees, though it is a matter for individual member states who will technically have to receive a request from Baghdad to comply with the EU arms embargo.

Federica Mogherini, the Italian foreign minister whose country holds the EU's rotating six-month presidency, said an agreement needed to be reached on "a strong and coordinated course of action".In a sign of the deep unease across the EU at the ease with which Isis forces are spreading across large areas of Syria and Iraq, the German foreign ministry warned of "an existential threat to ethnic and religious minorities in Iraq, for the state and for the whole region".

A spokesman for the ministry told Reuters: "The German government thinks it is very important that there is a European response … it is particularly important to have a coherent European response in terms of equipment and humanitarian aid."

The Elysée Palace appeared to lay the ground for countering Isis by supplying French arms to the Kurds. In a statement President François Hollande's office said: "In order to respond to the urgent need expressed by the Kurdistan regional authorities, the president has decided, in agreement with Baghdad, to deliver arms in the coming hours. France intends to play an active role by providing, along with its partners and in liaison with the new Iraqi authorities, all the assistance required."

Downing Street has no plans to supply British weapons directly to the Kurds on the grounds that the peshmerga forces are trained to use Soviet-era weapons. But there appears to be no agreement within the coalition to supply arms amid signs that Nick Clegg is ruling out any British involvement in Iraq beyond helping with humanitarian relief.

The prime minister announced that Britain would help to restock Kurdish supplies by transporting ammunition from eastern European countries. The RAF will be flying in weapons from former Warsaw pact countries in eastern Europe to the Kurds who are trained in the use of such weapons.

David Cameron, who returned from his Portuguese holiday a day earlier than expected to take command of Britain's response to the crisis, told the BBC: "We do support the Kurds and we should continue to support the Kurds. In terms of the ammunition they are getting – Britain is going to be playing a role in helping to get that to them. What they want is ammunition and weapons like they have been using. That is what is being delivered to them and Britain is playing a role in helping to make sure that happens."

Cameron said Britain would play a leading role in helping to airlift refugees from Mount Sinjar. He said: "We need a plan to get these people off that mountain and get them to a place of safety. I can confirm that detailed plans are now being put in place and are underway and that Britain will play a role in delivering them. I think the first thing is to deal with this desperate humanitarian situation, with people who are exposed, starving, dying of thirst on this mountainside – getting them to a place of safety."

Cameron said he had no plans to recall parliament. He said: "This is a humanitarian operation that Britain is involved in so I don't think it is necessary to recall parliament for that. But of course I always keep this issue under review and were things to change then obviously that is something that could be done."

But the disclosure that SAS soldiers are on the ground is likely to intensify calls for a recall of parliament. Sir Menzies Campbell, the former Liberal Democrat leader, led the calls on Wednesday after it emerged that RAF Chinook helicopters would help with the rescue mission on Mount Sinjar.

Campbell told Sky News: "We have heard from the prime minister that we are increasing our obligation. It is certainly still part of the humanitarian effort. But if we are taking part in a rescue operation that can only be through the use of helicopters – then helicopters, by their nature, are subject to the risks from surface-to-air missiles. We know that the Isis jihadis have captured some of those.

"When you are putting troops or any personnel into harm's way you really do have an obligation to come to the House of Commons and to explain. "I think it is in the interests of the government to come to the House of Commons and explain. For the moment at least the government has a story to tell. We are helping with the humanitarian effort, we are helping with the intention to provide more weapons to the peshmerga – helping to move these weapons."