• 28 more civilian deaths

US Defence Secretary Jim Mattis said on Thursday that French special operations forces arrived in Syria over the past two weeks to help boost US-led efforts against the Islamic State group.

Speaking to senior lawmakers in Washington, Mattis responded to a question about whether the United States was planning on pulling out of Syria — something President Donald Trump has said would happen “very soon.” Right now, “we are not withdrawing,” Mattis told the Senate Armed Services Committee.

“You'll see a reenergised effort ... You'll see increased operations on the Iraqi side of the border, and the French just reinforced us in Syria with special forces here in the last two weeks. This is an ongoing fight right now,” he said.

Trump on Tuesday appeared to walk back his vow to yank US troops from Syria, saying the United States wanted to “leave a strong and lasting footprint ” in the country. Currently, about 2,000 US troops are in Syria, most of them commandos.

France is a longstanding member of the international coalition fighting IS in Iraq and Syria, and helped bombard the militants in the Mosul area during the Iraqi operation to recapture the city.

France, along with the US and Britain, also took part in the April 14 cruise missile strikes against Syrian President Bashar al-Assad's chemical weapons-related facilities.

28 more civilian deaths

The US-led coalition fighting the Islamic State group in Syria and Iraq acknowledged on Thursday the deaths of another 28 civilians, increasing the overall toll of non-fighters killed to at least 883.

The coalition said in a statement that it had completed a review in March of 49 reports of potential civilian casualties from air and artillery strikes, of which all but three were deemed not credible.

These three incidents occurred in Iraq and Syria last year.

On May 25, near Al-Mayadin in Syria's eastern province of Deir Ezzor, 15 people were killed during an air strike on an IS “media centre and headquarters.”

“The investigation assessed that although all feasible precautions were taken and the decision to strike complied with the law of armed conflict, unintended civilian casualties unfortunately occurred,” officials said in a statement.

An April 27, 2017 strike on an IS headquarters in the Syrian city of Raqa saw 11 civilians killed, and a May 16 strike saw two people killed.

Investigators were still looking at another 476 reports from the campaign.

The coalition conducted a total of 29,254 strikes between August 2014 and the end of March 2018 in Iraq and Syria.

Monitoring group Airwars says the number of civilian deaths acknowledged by the US-led coalition is well below the true toll of the bombing campaign, estimating that at least 6,259 civilians have been killed.

The US-led operations to fight IS in Iraq and Syria have largely wound down, with the jihadists ousted from more than 98 percent of the territory they once held.

The coalition's toll of non-fighters killed dates from 2014.