According to US, the 10,000 suspected Islamic State fighters are being held in northern Syria by Western-allied Kurdish fighters.
Blinken, who is in Rome, was speaking at the opening of a gathering to renew international efforts to combat the Islamist militia.
In his opening remarks, Blinken said, "This situation is just untenable. It just can't persist indefinitely. The us continues to urge countries of origin, including coalition partners, to repatriate, rehabilitate, and where applicable, prosecute their citizens."
Suggesting another significant thanks to defeat Islamic State, Blinken said that addressing threats from the group outside Iraq and Syria, especially from Africa, on a permanent basis is required.
A Human Rights Watch report in March confirmed that the Kurdish-led Syrian Democratic Forces are holding quite 63,000 women and youngsters of suspected Islamic State fighters from quite 60 countries in two camps surrounded by wire .
An offshoot of al Qaeda, the Islamic State has captured major chunks of Iraq and Syria for seven years now. The terrorist organization has imposed a reign of terror with public beheadings and attacks by foreign supporters.
Even after the Islamic State was declared militarily defeated in 2017, it's waged a unbroken insurgency across parts of parts of northern Iraq and a porous border with neighbouring Syria.
The Islamic State group has lost most of its territory in Syria and Iraq, where it once ran a huge self-styled caliphate marked by a unprecedented campaign of brutality against religious minorities and ladies .
Indicating their firm holding over terrorism activities, Islamic State militants have taken responsibility for quite 25 deadly attacks within the recent months.
In a crowded Baghdad, IS bombed a market in January which killed quite 30 people.
Militant groups linked to al Qaeda and Islamic State have also grown stronger in recent years, despite the deployment of thousands of regional, Western and UN troops across West Africa's Sahel region.
