Downing Street said there had been no request from Washington for the UK to contribute to air strikes yet.
"Our focus has not been on air strikes. It is not under discussion at the moment,” a Uk government spokeswoman said. She also insisted that the UK would not send combat troops to Iraq.
The British response followed a report in The New York Times, citing unnamed US officials as saying that Britain and Australia would be willing to join an air campaign against forces of the ISIL in Iraq and Syria.
According to reports, the US is poised to ask Britain and Australia to support air strikes in Northern Iraq.
President Obama is set to authorize airstrikes and aid drops around the Iraqi town of Amerli, home of Iraq's Turkmen minority, where 12,000 people have been under siege by ISIL extremists for two months. US officials have compared that siege to the similar humanitarian crisis faced by thousands of Yazidis who were trapped on Mount Sinjar.
Nickolay Mladenov, the United Nations special representative for Iraq, has said that the situation in Amerli "demands immediate action to prevent the possible massacre of its citizens."
It comes after repeated calls from UK politicians and several senior figures in the military for Britain to support air strikes.
Currently, the role of RAF (Royal Air Force) has been limited to surveillance and aid drops and PM David Cameron has categorically ruled out ground troops in Iraq. “We have been working together with the US already in terms of providing surveillance,” the spokesperson said, adding, however that the UK is not currently cooperating with the US on air strikes.
UK ministers have not ruled out air strikes, but they have consistently played down the prospect of Britain getting involved in a full-scale military campaign.
"Britain is not going to get involved in another war in Iraq," Cameron told BBC1's Breakfast program last week.
"We are not going to be putting boots on the ground. We are not going to be sending in the British army."
Britain is already supplying weapons from Eastern European countries to Kurdish peshmerga fighters, and Philip Hammond, the Foreign Secretary, has indicated that it could also offer training in Baghdad. Officials have repeatedly insisted that Britain's focus is on helping the Iraqis and Kurds fight ISIL by providing assistance with surveillance and supplying equipment.
Air strikes would represent a significant escalation in Britain's role in Iraq.
The US, meanwhile, has been carrying out air strikes against ISIL targets in Iraq. It has also begun reconnaissance flights over Syria in preparation for a possible cross-border expansion of its aerial campaign against ISIL militants in Iraq.
NJF/NJF