Trump was set to meet Wednesday in Saudi Arabia with Syrian President Ahmad al-Sharaa, the onetime insurgent who last year led the overthrow of former leader Bashar Assad. He said the effort at rapprochement came at the urging of Crown Prince Mohammed bin Salman, the Saudi de facto ruler, and Turkish President Recep Tayyip Erdogan.

In December, a consortium of rebel factions led by the group Hayat Tahrir al-Sham unexpectedly toppled the dictator Bashar al-Assad, whose family had ruled Syria for five decades. The new regime in Damascus inherited a country ruined by a 13-year civil war.

A short statement released by the office of President Ahmad al-Sharaa did not give a reason why he will not attend the summit but an invitation by the Iraqi government last month trigged sharp political divisions in Iraq. The summit is scheduled to be held in Baghdad on Saturday.

A former al-Qaeda member, Syria's new leader Ahmed al-Sharaa is seeking to rework his approach to the West after embarking on a mission to actively woo the US, in a bid to rebuild the country, which has been under sanctions for over a decade.

The remains of 30 people believed to have been killed by the militant Islamic State group have been found in a remote Syrian town in a search led by Qatari search teams along with the FBI