(Reuters) - The U.S. State Department said on Monday it might talk with Iran about promoting regional stability, noting it had been open to including Iran in past efforts to achieve a Syrian peace deal if Tehran had altered its policy.

But it drew a distinction between talking to Iran about issues beyond its nuclear program and actually working with Tehran on such matters, something Washington has ruled out.

State Department spokeswoman Marie Harf made the comments when asked about a call by Iranian Foreign Minister Mohammed Javad Zarif in a New York Times opinion piece for regional dialogue to address the crises in countries such as Iraq, Syria and Yemen.

Washington was put in an awkward position since it blames Tehran for much of the instability and because it does not wish to upset Gulf Arab allies who fear a nuclear deal being negotiated with Iran may pave the way to a wider U.S.-Iranian entente.

The State Department appeared to be treading a careful line so as to not shut the door entirely to dialogue with Iran while not alienating Gulf Arab allies like Saudi Arabia, which believes Iran is bent on regional domination.

Asked if the United States might discuss regional issues as it has in the past with Iran if Tehran pursued policies more in line with U.S. objectives, Harf replied: "Maybe."

She said Washington had been open to including Tehran in a second round of Syria peace talks in 2014 had Iran embraced the 2012 "Geneva Communique," which called for a political transition, but left ambiguous the fate of Syrian President Bashar al-Assad.

In the end, Iran did not sign on to the Geneva Communique and did not participate in the January 2014 "Geneva II" meeting.

Harf sought to draw a distinction between the possibility of talking to the Iranians and the reality of "working with" them, suggesting that was a line Washington would not cross.

"We've always said we won't be coordinating or working with the Iranians, and there's a difference between discussing and working with," she said.

The White House suggested that it viewed the Iranian foreign minister's appeal as disingenuous, particularly regarding Yemen. The United States says Iran has armed Yemen's Houthi rebels, who have taken control of much of the country.

The debate over regional unrest comes against the backdrop of negotiation between Iran and Britain, China, France, Germany, Russia and the United States on a deal to curb Iran's nuclear program in exchange for relief from economic sanctions.

Sunni-ruled Gulf Arab states fear that an accord would let Iran devote more cash and energy to its Shi'ite proxies in Syria, Iraq, Lebanon and Yemen, escalating those conflicts.

By Reuters