The Pentagon says there are about 2,000 US troops in Syria.
Mattis also said that the United States was adjusting its support to the Syrian Democratic Forces, a mix of Kurdish and Arab troops that have led the US-backed fight against ISIS in Syria, suggesting that offensive weapons would no longer be provided to the Kurdish elements of the SDF, a change long sought by America's North Atlantic Treaty Organisation ally Turkey.
A Pentagon official said on Tuesday the U.S. military plans on staying in Syria as long as necessary to ensure the Islamic State group does not return.
"The campaign to defeat ISIS is now in a new phase in Iraq and Syria", Manning said.
"We are going to be in Syria for some time yet".
Manning announced the new official figure for American servicemembers in Syria on Wednesday, saying Defense Secretary Jim Mattis wants to increase transparency about where and how troops are deployed.More news: Analyst's Rankings to Lookout: Occidental Petroleum Corporation (OXY), Globalstar, Inc. (GSAT)
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The revision changes long-held procedures to account for troops at the Pentagon. It's not clear if that release and subsequent reports by Al-Monitor and other news outlets prompted the long-planned revision.
The U.S. military, along with other nations in a US-led coalition, began bombing IS in late 2014 but until now has largely declined to address what its role in the tangled conflict might be after the jihadists are beaten.
In his statement Tuesday, Pahon criticized Russian Federation and the regime of Syrian President Bashar al-Assad as impediments to stabilizing the situation there, saying that countering ISIS, al Qaeda and other terrorist groups is not of the "foremost priority" of Russian Federation and Syria.
"Current estimates are that there are less than 3,000 #Daesh fighters left - they still remain a threat, but we will continue to support our partner forces to defeat them", U.S. Army Colonel Ryan Dillon tweeted, using an Arabic acronym for ISIL. Speaking in California this weekend, White House national security adviser H.R. McMaster said that as much as 80% of pro-Assad forces in Syria are proxy forces controlled by Iran. "Nor do they appear to be serious about the withdrawal of Iranian-backed militias".
By September, the US-backed coalition trained 8,500 SDF troops in Syria and provided vehicles and equipment to 40,000 troops in the Arab and Kurdish units.
Secretary of Defense James Mattis told reporters Friday that the U.S. military mission in Syria was being reconfigured to better support diplomatic objectives, including the UN-led Geneva process aimed at bringing an end to the Syrian Civil War. "That's local forces. That's people who make certain that [IS] doesn't come back", Mattis said. The Pentagon's budget for the new fiscal year will provide $13 billion for the operation next year, including $1.8 billion to train and equip partner forces in Iraq and Syria.