Obama vows to step up action against ISIS

US President Barack Obama on Monday confirmed the death of Mohammed Emwazi, a Briton known as ''Jihadi John'', in an air strike last month and warned the Islamic State (ISIS), ''You are next.''

Obama promised to speed up the US-led military campaign against the ISIS in both Syria and Iraq, acknowledging that the reaction has been slow as the extremist group has expanded its reach.

Speaking at the Pentagon, he added that a group of American special operations commandos has begun working with local fighters in Syria to "tighten the squeeze" on Raqqa, ISIS' stronghold.

The administration announced in late October that Obama had approved sending up to 50 special operations troops to Syria on the first open-ended mission by US ground forces in Syria.

He cited this as an example of aggressive action, in addition to increased efforts to target the Islamic State's revenue base of the oil infrastructure in Syria.

While Republican presidential candidates including Ted Cruz have called to "carpet bomb them into oblivion", Obama has taken the more tactful approach, saying, "We have to be smart, targeting ISIL surgically, with precision" airstrikes while local forces do the ground combat.

Obama made his eight-minute address after having a meeting with his national security council.

''As we squeeze its heart, we'll make it harder for ISIL to pump its terror and propaganda to the rest of the world.

''This continues to be a difficult fight. ISIL is dug in, including in urban areas, and they hide behind civilians, using defenceless men, women and children as human shields. So even as we're relentless, we have to be smart, targeting ISIL surgically, with precision,'' Obama said flanked by Vice-President Joe Biden, the defence secretary, Ash Carter, and three military generals.

Obama listed several prominent ISIS leaders, commanders and killers who have been taken out, including Emwazi, ''who brutally murdered Americans and others''.

''So far ISIL has lost about 40 per cent of the populated areas it once controlled in Iraq, and it will lose more … ISIL's lost thousands of square miles of territory it once controlled in Syria and it will lose more. The special forces that I ordered to Syria have begun supporting local forces as they push south, cut off supply lines and tighten the squeeze on Raqqa,'' Obama said.

Emphasizing that ISIS was losing the ''propaganda'' war, the President said that the world had starts to see them as the ''thugs, thieves and killers'' they truly were.