DHAKA: Iran’s Supreme Leader has approved co-operation with the US as part of the fight against Islamic State in northern Iraq.

The sources told BBC on Friday.

Ayatollah Khamenei has authorised his top commander to co-ordinate military operations with the US, Iraqi and Kurdish forces.

Shia Iran regards the extremist Sunni Islamic State (IS) group, which views Shias as heretics, as a serious threat.

Iran has traditionally opposed US involvement in Iraq, an Iranian ally.

However last month US air strikes helped Iranian-backed Shia militia and Kurdish forces break a two-month siege by Islamic State (IS) of the Shia town of Amerli.

IS has taken over swathes of northern and western Iraq and eastern Syria in recent months.

US forces began carrying out air strikes on IS positions in August after they took over several cities in northern Iraq.

Now, Iran seems to have taken steps to work closer with the United States.

Sources say Ayatollah Khamenei has sanctioned Qasem Soleimani, the commander of the Quds force - the extraterritorial arm of the Revolutionary Guards - to work with forces fighting IS, including the US.

BDST: 1914 HRS. SEP 5, 2014