America will not shirk the responsibilities of leadership in the fight against the Islamic State group, Mike Pompeo has said.

The US Secretary of State was trying to allay fears that President Donald Trump’s decision to withdraw forces from Syria could jeopardise gains against the militants there and neighbouring Iraq.

President Trump’s announcement in December shocked US allies and led to the resignations of Defence Secretary Jim Mattis and the top US envoy to the anti-IS coalition, Brett McGurk.

US Syria
Secretary of State Mike Pompeo addresses the Global Coalition to Defeat Isis meeting (Alex Brandon/AP)

While the withdrawal would fulfil a Trump goal, US military leaders have pushed back for months, arguing IS remains a threat and could regroup.

US policy had been to keep troops in place until the extremists are completely eradicated. Fears that IS fighters are making a strategic manoeuvre to lay low ahead of the US pullout has fuelled criticism that President Trump telegraphed his military plans — the same thing he accused President Barack Obama of doing in Afghanistan.

Mr Pompeo told foreign ministers and senior officials from the 79-member, US-led 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.

IS has lost more than 99% of the territory it once held in the two countries.

“America will continue to lead in giving those who would destroy us no quarter,” Mr Pompeo said.

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

He said the fight is entering a new stage where those allied against IS must confront a “decentralised jihad” with more than military force.