Isis could regain its lost territory in a matter of months after troops withdraw from Syria, according to a draft Pentagon report.

Donald Trump announced last month that the US would withdraw 2,000 US troops from Syria on the grounds the militant group no longer pose a threat.

He doubled down on his claim this week, when he wrote on Twitter: “We’ve beaten them. Caliphate will soon be destroyed, unthinkable two years ago.”

But the Department of Defense Inspector General Quarterly Report, due to be released mext week, appears to contradict that claim.

It claims Isis is determined to rebuild a physical caliphate, NBC News reported. With no military pressure on the terror group, it could retake land in Syria within six to 12 months.

Syria at war: Fleeing the caliphate Show all 14 1 /14 Syria at war: Fleeing the caliphate Syria at war: Fleeing the caliphate Trucks full of women and children arrive from the last Isis-held areas in Deir ez-Zor, Syria Richard Hall/The Independent Syria at war: Fleeing the caliphate Zikia Ibrahim, 28, with her two-year-old son and 8-month-old daughter, after fleeing the Isis caliphate Richard Hall/The Independent Syria at war: Fleeing the caliphate Trucks full of women and children arrive from the last Isis-held areas in Deir ez-Zor, Syria. Richard Hall Richard Hall/The Independent Syria at war: Fleeing the caliphate Men who fled the last Isis-held area of Syria line up to be questioned by American and Kurdish intelligence officials Richard Hall/The Independent Syria at war: Fleeing the caliphate Trucks full of women and children arrive from the last Isis-held areas in Deir ez-Zor, Syria. Richard Hall Richard Hall/The Independent Syria at war: Fleeing the caliphate A young girl pulls her belongings after arriving Richard Hall/The Independent Syria at war: Fleeing the caliphate An SDF fighter hands out bread to women and children after they arrive Richard Hall/The Independent Syria at war: Fleeing the caliphate Sita Ghazzar, 70, after fleeing from the last Isis-held territory in Syria Richard Hall/The Independent Syria at war: Fleeing the caliphate A family from Russia who recently fled the last Isis-held area of Syria Richard Hall/The Independent Syria at war: Fleeing the caliphate Trucks full of women and children arrive from the last Isis-held areas in Deir ez-Zor, Syria. Richard Hall Richard Hall/The Independent Syria at war: Fleeing the caliphate Trucks full of women and children arrive from the last Isis-held areas in Deir ez-Zor, Syria. Richard Hall Richard Hall/The Independent Syria at war: Fleeing the caliphate Trucks full of women and children arrive from the last Isis-held areas in Deir ez-Zor, Syria. Richard Hall Richard Hall/The Independent Syria at war: Fleeing the caliphate Trucks full of women and children arrive from the last Isis-held areas in Deir ez-Zor, Syria. Richard Hall Richard Hall/The Independent Syria at war: Fleeing the caliphate Richard Hall Richard Hall/The Independent

The Republican-led US Senate advanced a largely symbolic legislation earlier this week opposing the president’s plans to withdraw troops from both Syria and Afghanistan.

The Senate voted 68-23 in favor of a non-binding amendment drafted by majority leader Mitch McConnell saying it was the sense of the Senate that Islamic militant groups in both countries continue to pose a “serious threat” to the US.

US intelligence chiefs have said Isis would continue to pursue attacks from Syria and Iraq against regional and Western adversaries, including the US, after Washington withddraws its troops.

Isis is expected to lose the final bits of its territory in Syria to US-backed forces within the next couple of weeks, acting US defence secretary Patrick Shanahan said earlier this week, even as US intelligence chiefs said the group would still pose a threat to regional and Western adversaries.

The Kurdish-led Syrian Democratic Forces are preparing for a final showdown with Isis in eastern Syria after helping to drive the fighters from the townd and cities that once formed the group’s self-proclaimed caliphate.

Isis fighters in eastern Syria are pinned down in a tiny pocket with their wives and children, forcing the US-backed militia to slow its advance to protect civilians.

Trump says Syria is ‘sand and death’

The annual Worldwide Threat Assessment from the Directorate of National Intelligence (DNI), released earlier this week, also contradicted assertions by Mr Trump and other top administration officials that Isis had been defeated in Syria and Iraq, saying the group still commanded thousands of fighters and posed a long-term threat to both countries.

During a congressional hearing director of national intelligence Dan Coats said Isis and other militant groups would remain active for years around the world.