David Cameron has said "detailed plans" are being made for an international mission to rescue the Yazidis stranded in the mountains of northern Iraq.
The Prime Minister said Britain would "play a role in delivering" the rescue of thousands of ethnic minority Kurds who have been driven into Mount Sinjar by the Islamic State fighters.
Mr Cameron stressed it would be a "humanitarian operation" and said there was no need to recall Parliament to discuss it. He was speaking after chairing a Cobra meeting following his return from the family holiday in Portugal.
RAF Tornado jets will carry out surveillance mission in Iraq
He has come under increasing pressure to commit to military action in Iraq. A growing number of MPs have told Sky News it is time for the UK to join US airstrikes to stop the advance of the extremists.
The UK has stepped up its aid drops in northern Iraq and is sending a "small number" of RAF Chinook helicopters to the region. It has also already sent RAF Tornado jets equipped with sophisticated surveillance equipment to gather intelligence.
Mr Cameron would not confirm whether the Chinooks would be used to airlift people off the mountains. He added that Britain would continue transporting weapons for the Kurdish forces, who have been outgunned by the jihadists.
Downing Street has consistently resisted calls for UK forces to join the US in taking military action against IS. It has also rejected demands for Parliament to be recalled to debate the crisis.
The Prime Minister has been on a 10-day holiday in Portugal
Thousands of Kurdish ethnic minority Yazidis have been driven into the Sinjar mountains to escape the onslaught of the militants, who have butchered their way through the north of Iraq leaving mass graves of victims in their wake.
The United Nations estimates that between 20,000 and 30,000 people from the ancient Yazidi community remain stranded, others have perished, unable to get food or water to survive, while some have been rescued by Kurdish forces.
Sky's Political Correspondent Sophy Ridge said of the 23 MPs she had spoken to, 18 said they would support military intervention and many urged Mr Cameron to recall Parliament.
Significantly, seven of those MPs who supported action voted against using military force in Syria to end the humanitarian crisis there.
Conservative MP Nick de Bois said: "Whether you support air strikes or not, and they should be on the table for urgent consideration, Parliament has both the moral obligation and a duty to our constituents to examine and advise the Government on whether we should take that step.
The Yazidi community has fled into the Sinjar mountains
"Every day in this humanitarian crisis matters and that's why we should be recalled."
Another unnamed MP said: "It's very different from Syria, where the Government had no plan or conception of what might work. Here we have the Kurds on the ground. Also, recall of Parliament seems essential given world events."
It comes as British commanders with experience in Iraq have urged the Prime Minister to consider taking military action with Colonel Tim Collins warning the ancient civilisations in Iraq could be "extinguished".
Tony Abbott, in London on Tuesday, hinted forces could return to Iraq
Col Collins claimed the Government had "left for lunch" on the issue, and accused politicians of refusing to accept the "moral responsibility" to act.
Writing in the Daily Telegraph, he said: "Britain helped create Iraq in 1920 and we have a moral responsibility to help."
A YouGov poll carried out for The Times suggests support for the British bombing of militants in Iraq is now at 40%. Some 36% of those asked were opposed to the UK taking action.
US service members prepare humanitarian aid for the Yazidis in Iraq
After talks with Foreign Secretary Philip Hammond in London on Tuesday, Australian Prime Minister Tony Abbott indicated his country's combat forces could return to Iraq but stressed it would be to "prevent genocide" on a "fundamentally humanitarian mission".
Germany has pledged to deliver "non lethal" military aid, including armoured vehicles, helmets and night vision goggles, to the Iraqi army. France was expected to deliver arms to Kurdish forces later on Wednesday.
Former Conservative Defence Secretary Liam Fox also said it was time RAF jets were sent in to join US airstrikes. Writing in the Daily Mail, he said sending in aid was not enough.
The US has sent another 130 military advisers to northern Iraq to assess the scope of the humanitarian mission.