"We have not seen the US do anything for now. Any time the Americans start to take action against terrorist groups, we can consider that."
The largely Shia Iranian government has close links to the Shia Iraqi government that came in to power after former leader Saddam Hussein was overthrown.
Both are seen as infidels by the Sunni group Isis.
Rouhani dismissed reports that troops had already been sent to Iraq by the Iranian government, saying that the "engagement of forces had not been discussed."
The Iraqi government has been under serious pressure this week with insurgents from the extremist group Isis country taking key cities in the north of the country and forcing the Iraqi army to retreat.
Isis, whose stated aim is the establishment of a caliphate governed under a strict interpretation of Sharia law, took the country's second biggest city, Mosul, on Thursday and there are real fears that they could reach Baghdad in the near future.
There have been reports that Isis has carried out terrible atrocities during their campaign through Iraq.
According to reports, Isis members have been accused of rape, torture and the execution of thousands.
On Friday, Rupert Colville said the UN's mission in Iraq (UNAMI) had received reports that "the number of people killed in recent days may run into the hundreds and the number of wounded is said to be approaching 1,000."
The gains made by Isis have led to many in the international community becoming increasingly worried about the threat of Isis and Iraqi authorities' inability in dealing with it.
Barack Obama has consistently said that Isis could pose a threat to "American interests" and that Iraq would need additional support to "break the momentum of extremist groups and bolster the capabilities of Iraqi security forces".
Earlier today, a senior US official told the Guardian that the US were stepping up their and discussions about a potential air strike campaign was under "serious discussion."
In his speech today, Rouhani acknowledged the possibility of America assisting Iran and left the door open for a potential alliance between Iran and the US in combating Isis.
-The Independent