At least 200,000 Islamic State militants are reportedly fighting in Iraq and Syria against the international coalition, far larger than what has previously been estimated by the CIA, a senior Kurdish leader revealed.

While intelligence officials had reported the terrorist organization as having up to 31,500 fighters, it is now being speculated that ISIS has recruited an army hundreds of thousands strong, further proven by their ability to simultaneously cover and attack multiple widely separated fronts in Iraq and Syria, The Independent reported.

"I am talking about hundreds of thousands of fighters because they are able to mobilize Arab young men in the territory they have taken," Fuad Hussein, the chief of staff of the Kurdish President Massoud Barzani, told The Independent in an exclusive interview on Sunday, additionally estimating that ISIS "rules a third of Iraq and a third of Syria with a population of between 10 and 12 million living in an area of 250,000 square kilometers (155,343 square miles), the same size as Great Britain."

Earlier this week, General Martin Dempsey, the chairman of the U.S. Joint Chiefs of Staff, told Congress that an efficient army of 80,000 men would be required to defeat the terrorist group. Then on Friday, he made a surprise visit to Baghdad "to get a sense from our side about how our contribution is going."

Specifically, ISIS's strength in numbers can be witnessed through the rapid growth of its army forces, which are not only battling Kurds in northern Iraq and Syria at the same time, but also fighting against the Iraqi army close to Baghdad.

"They are fighting in Kobani," said Hussein. "In Kurdistan last month they were attacking in seven different places as well as in Ramadi [capital of Anbar province west of Baghdad] and Jalawla [an Arab-Kurdish town close to Iranian border]. It is impossible to talk of 20,000 men or so."

"In September, the CIA produced an estimate of ISIS numbers which calculated that the movement had between 20,000 and 31,500 fighters," according to The Independent. "The underestimate of the size of the force that ISIS can deploy may explain why the U.S. and other foreign governments have been repeatedly caught by surprise over the past five months as ISIS inflicted successive defeats on the Iraqi army, Syrian army, Syrian rebels and Kurdish peshmerga (armed Kurdish fighters).

ISIS, which has continuously taken to social media to publicize the beheadings of Western hostages, has also developed an effective cocktail of tactics, including suicide bombers, mines, snipers and making use of U.S. equipment captured from the Iraqi army such as Humvees, artillery and tanks.

"They will fight until death, and are dangerous because they are so well-trained," said Hussein. "For instance, they have the best snipers, but to be a good sniper you need not only training on how to shoot, but discipline in staying put for up to five hours so you can hit your target."

Over the past five months especially, ISIS has created a formidable military force, Breitbart reported.

"We are talking about a state that has a military and ideological basis," said Hussein, "so that means they want everyone to learn how to use a rifle, but they also want everybody to have training in their ideology, in other words brainwashing."

In addition, a salary of $400 per month and the chance to contribute to the growing threat and success of the Islamic State keeps attracting young recruits to the terrorist organization, according to a study by the National Security Advisor's office in Baghdad, which also cited a recent incident where 100 jihadists entered a district and were able to immediately recruit five and 10 times their original number.

Meanwhile, the ISIS leader, Abu Bakr al-Baghdadi, has reportedly ordered the terrorist organization to start minting gold, silver and copper coins for its own currency, the Islamic Dinar, according to a website affiliated with the group.

In a post made late Thursday, ISIS followers were instructed to start minting the coins as a step toward changing the "tyrannical monetary system" modeled on Western economies, which, according to al-Baghdadi, has "enslaved Muslims."