The United States discussed the crisis in Iraq with Iran on the sidelines of nuclear talks in Vienna, a US official said Monday.

“The issue did come up briefly with Iran on the margins of the P5+1 in Vienna today, separate from our trilateral meeting” which had included the EU, a senior State Department official said in a statement, asking not to be named.

State Department deputy spokeswoman Marie Harf confirmed to CNN television that there were “brief discussions.”

It is yet to be determined “if we want to keep talking to Iran about Iraq,” she added.

Another US official told AFP no further bilateral talks on Iraq were likely to be held in Vienna.

US and Iranian delegations were already in Vienna for talks on hammering out a treaty to rein in Tehran’s nuclear ambitions with global partners from the grouping known as the P5+1.

Any further bilateral “engagements” on Iraq “will not include military coordination or strategic determinations about Iraq’s future over the heads of the Iraqi people,” the State Department official said in the statement.

The talks come as militants from the Islamic State of Iraq and the Levant (ISIL) have pressed a lightning offensive in northern Iraq, capturing a vast swath of territory.

“We will discuss how ISIL threatens many countries in the region, including Iran, and the need to support inclusivity in Iraq and refrain from pressing a sectarian agenda,” the State Department statement said.