Iran has suspended a fifth round of talks with regional rival Saudi Arabia, Nour news, a website affiliated to Iran's top security body reported on Sunday.
Iraq's Foreign Minister Fuad Hussein said on Saturday his country would host a new round of Saudi-Iranian talks starting on Wednesday, reports Reuters.
The Saudi government media office CIC did not immediately respond to a Reuters request for comment.
"Iran has unilaterally suspended talks with Saudi Arabia," Nour news said without providing a reason. It said no specific date had been scheduled for a new round of talks.
Diplomats hope the opening of direct channels between Iran and Saudi Arabia will signal an easing of tensions across the Middle East after years of hostilities that have brought the region close to a full-scale conflict.
Regional rivals Iran and Saudi Arabia, which severed diplomatic ties in 2016, launched direct talks hosted by Iraq last year as UN-led efforts to end a war in Yemen stall.
They have held four rounds of talks in Iraq, with Baghdad hoping its mediation would stop the neighbours from seeking to settle scores on its territory. Saudi Arabia has described the talks as cordial but exploratory, while Tehran says they had gone a "good distance".
Saudi Arabia and Iran have backed opposing sides in regional conflicts and political disputes in Syria, Lebanon and Iraq for years, and Saudi Arabia has led an Arab coalition waging war against the Iran-aligned Houthi movement in Yemen since 2015.
Meanwhile, talks to revive the 2015 Iran nuclear deal face the prospect of collapse after a last-minute Russian demand forced world powers to pause negotiations for an undetermined time despite having a largely completed text.
Negotiators have reached the final stages of 11 months of discussions to restore the deal, which lifted sanctions on Iran in return for curbs on its nuclear programme.