In an interview with NBC's "Meet the Press," US Secretary of State John Kerry claimed that the US and the international coalition are "on the road" to defeating the Islamic State of Iraq and Syria.

The extremist group has lost 22 per cent of its territorial holdings to the coalition's ground forces, Kerry said, and this was achieved "without launching ... a major offensive." 

"We have taken out a significant proportion of the top leadership of ISIS. Their command and control facilities have been attacked, interrupting their command and control. They no longer can communicate the way they were, as openly. They no longer travel in convoys, as they were, as openly," Kerry told MSNBC.

The coalition was earlier brought under fire by DIA Director Lt. General Lt. Gen. Vincent Stewart, who told the House Armed Services Committee that ISIS has also established a foothold in North Africa outside the Middle East through affiliates in Algeria, Egypt and Libya.

Ashton Carter, nominee for defense secretary, also told Congress that there are reports that the Islamic State is also working to establish themselves in Afghanistan.

However, retired General John Allen, who serves as US envoy to the Islamic State, spoke to ABC in its "This Week" segment, and said that coalition has successfully delivered a "hard blow" to the extremists. Allen also referred to the US strategy as "comprehensive."

Allen pointed out the successes that have been achieved in the border town of Kobani in Syria, where Kurdish and Peshmerga units have successfully uprooted the Islamic State's presence with support from coalition aircraft.

Jordanian Minister of Foreign Affairs Nasser Judeh agreed with Kerry's assessment, telling ABC that ISIS is "on the run." While he is not confident of a quick win against the sizeable fighting force of the Islamic State, Judeh is optimistic that the joint forces will "prevail" in the end.

Kerry himself said that there is still "a lot to do" to bring down the Islamic State.

"We have said, since the beginning, this is a long-term operation, not a short-term one," he told MSNBC.