WASHINGTON: President Donald Trump is expected to declare near-total triumph over the Daesh group in Syria in his State of the Union address, but US defense officials are increasingly fearful that the militants are simply biding their time until the Americans leave the battlefield as planned.

Daesh militants have lost territory since Trump’s surprise announcement in December that he was pulling US forces out, but military officials warn the fighters could regroup within six months to a year after the Americans leave.

A Defense Department watchdog report released Monday warned of just such a possibility.

The Daesh group “remains a potent force of battle-hardened and well-disciplined fighters that ‘could likely resurge in Syria’ absent continued counterterrorism pressure,” the report from the inspector general said.

However, the top commander of US forces in the Middle East, General Joseph Votel, told a Senate committee on Tuesday that of the 34,000 square miles of territory that Daesh once held, it now controls less than 20 square miles.

Votel told the committee that it was important to understand that even though the territory has been reclaimed, the fight against Daesh and "violent extremists" was not over and that the "mission has not changed."

"The coalition's hard-won battlefield gains can only be secured by maintaining a vigilant offensive against the now largely dispersed and disaggregated ISIS that retains leaders, fighters, facilitators, resources and the profane ideology that fuels their efforts," he said, using a term used to describe Daesh.

Votel said there are now between 1,000 and 1,500 Daesh fighters in the small area they still control in the southern part of the Euphrates River Valley near the Iraqi border. The remainder, he said, have "dispersed" and "gone to ground," suggesting they retain the potential to return.

Trump’s decision to leave Syria, which he initially said would be rapid but later slowed down, shocked US allies led to the resignations of Defense Secretary Jim Mattis and the top envoy to the anti- Daesh coalition, Brett McGurk.

The withdrawal will fulfill Trump’s goal of bringing troops home from Syria, but military leaders have pushed back for months, arguing that Daesh remains a threat and could regroup. US policy has been to keep troops in place until the extremists are eradicated.

Fears that Daesh fighters are making strategic maneuvers ahead of a US pullout could also fuel criticism that Trump is telegraphing his military plans — the same thing he accused President Barack Obama of doing in Afghanistan.

US officials in recent weeks say Daesh has lost 99.5 percent of its territory and is holding on to fewer than 10 square kilometers of turf in Syria — an area smaller than New York’s Central Park. In late November and December that figure had been estimated at between 400 and 600 square kilometers, according to officials briefed on the matter.

But several defense officials said Monday that many fighters fled to ungoverned spaces and other pockets in the north and in the west and are likely hiding out until they can regroup.

Trump said in a weekend interview that the caliphate is “almost knocked out.”

“We’re at 99 percent right now, we’ll be at 100,” he said on CBS’ “Face the Nation.”

US officials say that Daesh fighters hold only several villages in the Middle Euphrates River Valley that amount to significantly less than 10 square kilometers. But they say they don’t expect that area to be cleared of militants for another several weeks, at best.

Officials say that overall, there are about 2,000 Daesh militants in Syria.

The Defense Department watchdog report warned that even with the Daesh forces on the run, the group “is still able to coordinate offensives and counter-offensives, as well as operate as a decentralized insurgency.”

The report, which covers October through December 2018, also includes a classified section that was provided to Congress and includes a more detailed Pentagon assessment on the impact of the troops’ withdrawal and the status of Daesh militants and other foreign fighters in Syria.

According to the report, US Central Command believes that Daesh fighters will continue to conduct “opportunistic attacks” on US troops as they withdraw. And it says, “If Sunni socio-economic, political, and sectarian grievances are not adequately addressed by the national and local governments of Iraq and Syria it is very likely that Daesh will have the opportunity to set conditions for future resurgence and territorial control.”

Central Command said that the Daesh group is “regenerating key functions and capabilities more quickly in Iraq than in Syria,” but unless there is sustained counterterrorism pressure, Daesh militants “could likely resurge in Syria within six to twelve months and regain limited territory” in the Middle Euphrates River Valley.

Despite Trump’s order to withdraw, American officials maintain that the goal remains the “enduring defeat” of the Daesh group and are moving ahead with a long-planned meeting of top diplomats from the 79-member US-led anti- Daesh coalition this week. The aim of the conference is to recommit the coalition to that aim and ensure that the departure of US troops does not overly complicate that mission.

Trump himself is expected to speak to the gathered foreign ministers at the State Department-hosted conference on Wednesday is widely expected to reiterate and expand on his anti- Daesh message from the State of the Union, officials said.