DAMASCUS, June 3 -- Syria's President Bashar al-Assad said the situation in Syria is witnessing big improvement, largely due to the retreat of the terror-designated groups.

The situation on the ground has become much better than what it used to be before, from a military perspective, Assad said during an interview, whose content was published by state news agency SANA on Saturday.

The president's remarks came as the Islamic State (IS) group is losing ground on several fronts, mainly in the Syrian desert in central Syria, the countryside of Aleppo province, and last but not least in the Raqqa province, the de facto capital of IS.

He also mentioned the retreat of the al-Qaida-linked Nusra Front.

Still, Assad said the military perspective is not enough, adding that terrorist ideology that is being spread in the region constitutes the biggest and most dangerous challenge.

He said defeating the terror groups relies on halting their support by countries such as Turkey, Qatar, Saudi Arabia and the Western ones like the United States, Britain and France.

Earlier in the day, the Syrian army and allied fighters have captured 1,400 square km from the IS in the Syrian desert over the past 24 hours, according to SANA.

It also said that at least 1,200 IS fighters were killed during a wide-scale military offensive in Aleppo.