INTERNATIONAL: The United States needs to make a decision to revive the Iran nuclear deal, Tehran's Foreign Ministry Spokesperson Saeed Khatibzadeh has said on Monday.

Talks to revive the 2015 Iran nuclear pact face the prospect of collapse after a last-minute Russian demand have forced world powers to pause negotiations for an undetermined time despite having a largely completed text.

"We are currently having a breather from the nuclear talks," said Khatibzadeh.

"We are not at a point of announcing an agreement now since there are some important open issues that need to be decided upon by Washington."

"As soon as we receive their decisions, we will be able to return to Vienna and reach a final agreement."

Tensions have been rising since Iran has attacked Iraq's northern city of Erbil on Sunday with a dozen ballistic missiles in an unprecedented assault on the capital of the autonomous Iraqi Kurdish region that appeared to target the United States and its allies.

Iran's Revolutionary Guards Corps have carried out the attack against Israeli "strategic centres" in Erbil, suggesting it was revenge for recent Israeli air strikes that have killed Iranian military personnel in Syria.