DONALD Trump has claimed that ISIS will be “100 per cent” defeated in Iraq and Syria by next week.

The US President today predicted that the terror group will have lost its final strongholds within days following "victory over victory".

He insisted the US would not relent in fighting the "sick and demented" extremists despite his decision to withdraw US troops from Syria.

Trump told representatives of a 79-member, US-led coalition fighting ISIS that the militants held a tiny percentage of the vast territory they once claimed as their "caliphate".

"It should be formally announced sometime, probably next week, that we will have 100 per cent of the caliphate," Trump said.

He added: “Over the past two years we have retaken 20,000 square miles of land; we have seen victory after victory after victory.

“We have retaken both Mosul and Raqqa. We’ve eliminated more than 60 high-value ISIS leaders.

“Tens of thousands of ISIS fighters are gone. They’re gone.”

US officials have said that ISIS has lost 99.5 per cent of its territory and is holding on to fewer than 5sq km in Syria in the Middle Euphrates River Valley.

"The United States military, our coalition partners and the Syrian Democratic Forces have liberated virtually all of the territory previously held by ISIS in Syria and Iraq," Mr Trump told foreign ministers.

But there are fears the impending US pullout will endanger those gains.

Trump told coalition members meeting at the State Department that while "remnants" of the group were still dangerous, he was determined to bring US troops home.

He called on coalition members to step up and do their "fair share" in the fight against terrorism.

Trump and Secretary of State Mike Pompeo defended the withdrawal decision, which shocked US allies and led to the resignation of Defense Secretary Jim Mattis.

But top military officials have pushed back for months, arguing ISIS remains a threat and could regroup.

US policy had been to keep troops in place until the extremists are completely eradicated.

Fears that ISIS fighters are making a strategic manoeuvre to lay low ahead of the US pullout have fuelled criticism that Trump telegraphed his military plans.

This is the same thing he accused President Barack Obama of doing in Afghanistan.

Pompeo told the coalition that the planned withdrawal "is not a change in the mission" but a change in tactics against a group that should still be considered a menace.

"In this new era, local law enforcement and information sharing will be crucial, and our fight will not necessarily always be military-led," he said.

Trump's announcement "is not the end of America's fight. The fight is one that we will continue to wage alongside of you."

He added: "America will continue to lead in giving those who would destroy us no quarter."

Yet senior military officials acknowledged to Congress on Wednesday that the pullout would complicate their efforts.

Owen West, the assistant secretary of defense for special operations, told the House Armed Services Committee that he shared Mattis' objections.

At the same hearing, Maj. Gen. James Hecker, vice director of operations for the Joint Chiefs of Staff said the withdrawal means "it is going to be difficult to keep up the pressure" on ISIS.

"There will be a decrease in the amount of pressure that we will be able to apply," he said.

"The concern is if we move our forces out of Syria that that may take some pressure off of the ISIS forces in Syria," Hecker said.

"So our mission is to try to figure out how we can continue to keep the pressure on in Syria without any boots on the ground."

Hecker said others would have to carry the burden once the US left. He did not offer specifics.

Pompeo called on the coalition to increase intelligence-sharing, repatriate and prosecute captured foreign fighters and accelerate stabilization efforts so IS remnants cannot reconstitute in Iraq, Syria or elsewhere.

He said the fight is entering a new stage where those allied against ISIS must confront a "decentralized jihad" with more than military force.
Pompeo mentioned the suicide bombing claimed by ISIS that killed four Americans two service members, a Pentagon civilian and a U.S. contractor in the northern Syrian town of Manbij last month.

Manbij was liberated from ISIS control in 2016.

The conference started hours after Trump, in his State of the Union address, lauded what he said was the near-complete victory over IS.

He also reaffirmed his determination to pull out the roughly 2,000 U.S. troops from Syria.

He had said in December that the pullout would proceed quickly.

In liberated areas across Syria and Iraq, ISIS sleeper cells are carrying out assassinations, setting up checkpoints and distributing fliers as they lay the groundwork for an insurgency that could gain strength as US forces withdraw.

Activists who closely follow the conflict in Syria point to signs of a growing insurgency.

Rami Abdurrahman, the head of the Britain-based Syrian Observatory for Human Rights, says IS still has 4,000 to 5,000 fighters, many likely hiding out in desert caves and mountains.

Defense officials believe many fighters have fled to ungoverned spaces and other pockets in the north and west.

A Defense Department watchdog report warned this week that even with the IS forces on the run, the group "is still able to coordinate offensives and counter-offensives, as well as operate as a decentralized insurgency."