U.S. Secretary of State Antony Blinken made an unannounced visit to Iraq on Friday to meet Prime Minister Mohammed Shia al-Sudani for talks on the future of neighbouring Syria.

Blinken is touring the region in the wake of the swift collapse of Bashar al-Assad's government in the face of an advance by Syrian opposition factions.

Assad's ouster took Washington by surprise and the outgoing administration of President Joe Biden is urging the victorious rebels, with whom it is scrambling to establish contacts, to create a government that eschews Islamist factions and is inclusive of Syria's minorities.

Blinken visited the U.S. embassy in Baghdad and said he spoke to Sudani about the situation in Syria.

The pair discussed "the conviction of so many countries in the region and beyond that, as Syria transitions from the Assad dictatorship to hopefully a democracy, it does so in a way that, of course, protects all of the minorities in Syria that produces an inclusive, non-sectarian government," Blinken said, adding that Syria should not become a "platform for terrorism".

"No one knows the importance of that more than Iraq, because of the ongoing presence of ISIS or Daesh in Syria, and we are determined to make sure that Daesh cannot reemerge," he said, referring to the Islamic State group.

A U.S. official told Reuters that Washington sees this moment as an opportunity to further push back Iran's influence in the region.

Iraq, which is led by a coalition of mostly Shi'ite political parties and armed groups close to Iran, is a major player in Tehran's so-called Axis of Resistance that includes Hamas in Gaza and Lebanese Hezbollah and has faced setbacks since Israel responded to Hamas' Oct. 7, 2023 attacks.

Iraq opted not to allow Shi'ite militias to intervene in Syria as Sunni rebels advanced and ultimately seized Damascus last weekend, despite Baghdad's concerns that unrest could spill over.

Thousands of Sunni fighters crossed from Syria into Iraq after the 2003 U.S. invasion and fueled years of sectarian killing before returning in 2013 as Islamic State to conquer a third of the country.

Opposition factions in Syria led by Hayat Tahrir al-Sham have disavowed al Qaeda and Islamic State and say they have no ambitions in Iraq.

As the rebels in Syria advanced, Iraq had amassed on its border thousands of fighters from its conventional military as well as the Popular Mobilization Forces, a security agency containing many Iran-aligned armed groups that previously fought in Syria.