WASHINGTON: The United States on Monday urged Washington's traditional foe Iran to act "in a non-sectarian way" as it engages in the security crisis in neighboring Iraq.

In recent years, Washington has usually demanded that Iran not meddle in the situation in Iraq, but last week's shock gains by Sunni rebels have left Baghdad appealing for outside help.

"We would push Iran to address problems in a non-sectarian way," State Department spokeswoman Jen Psaki said.

Psaki said there was a "possibility" that the United States and Iran could hold bilateral talks on Iraq in Vienna, on the sidelines of the latest round of international talks on Tehran's nuclear ambitions that began Monday.

Key to that possibility is the presence in Vienna of US Deputy Secretary of State William Burns, who held secret nuclear talks with Iran in 2013.