The U.S. military had as recently as November said the official troop count in Syria was 503.
Now that it's the first week of December, that official figure has shot up to 2,000, even though no new troops were deployed, and indeed over 400 had just left.
Manning said Wednesday that it took weeks for the Pentagon to release the new official number because military officials wanted to make sure that it was right.
"Operating under recognized worldwide authorities, the US military will continue to support local partner forces in Syria to stabilize liberated territory", Pahon said. Critics say the policy masked the true extent of U.S. forces fighting IS and prevented the USA military from using support troops, such as mechanics and equipment maintainers in-theater, creating greater reliance on contractors. Separately, the Pentagon also temporarily deployed Army Rangers to northern Syria over the summer, an attempt to keep the peace as Syrian Kurdish fighters liberated cities in areas where other armed groups were loyal to nearby Turkey.
"To ensure an enduring defeat of ISIS, the coalition must ensure it can not regenerate, reclaim lost ground or plot external attacks", he said.
"We will be in Syria as long as it takes to make sure ISIS does not have the ability to reestablish safe havens... and plan and conduct attacks", said Manning, including that the 78-member USA -led anti-ISIS coalition is committed to the effort.
Operations in both countries are shifting as the terrorist group shrinks, said Eric Pahon, another Pentagon spokesman. Gen. James B. Jarrard, told reporters during a news conference that there were about 4,000 USA troops in Syria.
He reiterated US support for the United Nations -led talks in Geneva peace talks. 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.
But U.S. military operations in Syria are expected to continue.
Though the RISF and SDF are still in place, US Defense Secretary James Mattis during a trip to the Middle East last week indicated that the Pentagon would draw down support for Kurdish-backed units that led the fight against IS.
Russia has claimed its presence is primarily to thwart jihadist groups but the Pentagon says only a tiny portion of Russian strikes have targeted IS.
Officials also said the Donald Trump administration's mission in Syria, backed by a US-led coalition of 73 nations, won't be subject to pre-imposed timelines. Mattis said last month that the United States "won't just walk away" from efforts it has made in the country, and will focus on creating safe zones for civilians as other efforts to stabilize the country continue.