George Osborne said Britain must tackle the Syrian crisis as sources in Paris revealed that president Francois Hollande is set to green light a new wave of French airstrikes.
Russia has reportedly already sent fighter pilots to the country after agreeing a military alliance with Iran.
Now David Cameron is under pressure from senior Tories to bring forward plans to extend RAF airstrikes into Syria as the migrant crisis deepens.
Today Mr. Osborne delivered the strongest indication yet that the Government is considering military action in the region as a way of ending a war that has forced tens of thousands of people to flee to Europe.
He said: “You have got to deal with the problem at source.”
“You need a comprehensive plan for a more stable, peaceful Syria – a huge challenge of course, but we can’t just let that crisis fester. We have got to get engaged in that.
“There are lots of things that we need to do and it is only by doing them all that you have a solution to this great, great challenge.”
His comments came after former Defence Minister Liam Fox said Britain should begin airstrikes in Syria to create safe havens within the country, where refugees can shelter without making the perilous journey to Europe.
He said: “The policy of attacking Isis in Iraq but not in Syria is patently absurd which not only makes us less effective militarily but diminishes us in the eyes of other partners in the coalition.
“Hand-wringing about the tragedy of the refugees is not enough. It is time that action was taken to deal with the root of the problem.”
However, Mr. Cameron has previously promised to put any plans for military action before parliament and he is thought to be reluctant to risk a bruising commons defeat over the issue.
The situation would be complicated further if Jeremy Corbyn is elected Labour leader, as he has vowed to oppose any military action in the Middle East.
The announcement came as military sources in France indicated that Mr. Hollande is set to approve a wave of airstrikes against Isis in Syria.
High level sources at the Elysee Palace told newspaper Le Monde that the French government has changed its stance on bombing Syria because of the growing migrant crisis in Europe.
There have been chaotic scenes in Hungary this week as the country struggles to cope with the sheer numbers of migrants and refugees descending on its borders.
More than 2,500 have died trying to make the perilous crossing into Europe, with many drowning in the Mediterranean after being crammed onto rickety smugglers’ boats.
European leaders have been savagely criticized for their response to the crisis, with deep divisions emerging between member states.
Yesterday Mr. Cameron bowed to intense public and political pressure and announced that Britain will take in “thousands more” refugees from the camps in countries bordering Syria.
His decision came just days after heartbreaking photos of two dead Syrian boys washed up on a Turkish beach began circulating online.
However, he came under fire after Express.co.uk revealed that not a single refugee lives in his posh Oxfordshire constituency.
Forty local councils across Britain have agreed to house refugees from Syria, but the Local Government Association has warned they will only be able to do so if significant resources are made available to them.