Daesh has seized more than 50 percent of Syria and is now present in 10 out of 14 provinces in the country, the Syrian Observatory for Human Rights said Thursday, Anadolu Agency reported.
The reported data came after Daesh took full control of Tadmur city, including the Palmyra world heritage site in Homs province.
"[Daesh controls] more than 95,000 square kilometers inSyria and exists in the provinces of Homs, al- Raqqa, Deir Ezzor, al- Hasakah, Hama, Aleppo, Damascus, Rif Dimashq, Daraa and al-Suwaydaa," the U.K.-based observatory said.
The statement added that Daesh also controls the majority of gas and oilfields in Syria. In Washington, the State Department denied the accuracy of the observatory's claims.
"We certainly don't deny that ISIL holds significant territory in Syria, but we don't agree with those calculations," spokeswoman Marie Harf said using a different acronym for Daesh. She stopped short, however, of outlining Washington's view of the amount of territory the group controls in Syria.