In recent days, Damascus and Moscow have stepped up warnings of an imminent assault on the province, which shares a border with Turkey and is dominated by Hayat Tahrir al-Sham, a jihadist alliance led by the former branch of Al-Qaeda in Syria.
"All eyes on the actions of Assad, Russia, and Iran in Idlib".
Iranian media quoted Zarif saying Idlib should be put back under control of the Syrian people, and that reconstruction efforts in Syria and the return of refugees should go forward.
Zarif said it was necessary to consult "with our Syrian friends" ahead of the September 7 summit, according to Fars.More news: US Open at a glance -- day 6
Syrian Foreign Minister Walid al-Muallem requested that Iran continue its support for Syria in a meeting in Damascus on Monday with visiting Iranian Foreign Minister Mohammad Javad Zarif, according to Fars News.
Assad's forces, backed by military support from Russian Federation and Iran, have recaptured major cities in recent years, often involving agreements with both opposition fighters and civilians that allowed them to flee to Idlib.
Syrian regime forces have gathered around the last opposition bastion in the northwestern province of Idlib near the Turkish border.
Idlib and the surrounding area is home to some 3 million people - almost half of them already displaced a couple of times by the civil war - choosing to live in opposition areas.
United Nations officials believe an offensive on Idlib would trigger a wave of displacement that could uproot an estimated 800,000 people and discourage refugees from returning home.More news: Italian GP: Hamilton denies Ferrari a home win; Lance Stroll 10th
Russia, which has yet to comment on the latest statement from the U.S. leader, has been working for weeks to establish humanitarian corridors in Idlib province.
Thousands of government troops have been surrounding the area, preparing for what appears to be a major assault.
The official denied reports that senior Syrian officials were at the site.
The US is concerned they could eventually be used to launch another chemical attack as well as a conventional assault.More news: Tottenham's Son Heung-Min Avoids Miltary Duty After Asian Games Triumph