Earlier this year, President Barack Obama declared the group had lost swathes of territory and said its fighters "realise their cause is lost".
The US president said the so-called Islamic State had lost 40 per cent of its "caliphate" in Iraq and 10 per cent in Syria, and had suffered numerous financial setbacks.
The number of Isis militants killed in US strikes has increased from 6,000 in January 2015 to 45,000 in July 2016, Time reports.
Isis has recently lost control of its last territories on the border with Turkey, isolating it from the rest of the world and strangling its ability to bring in new recruits.
