Islamic State re-enters Syria's ancient Palmyra city

Islamic State militants re-entered Syria's famed ancient desert city of Palmyra on Saturday, after being forced out by government forces eight months ago, a monitor said.

"IS entered Palmyra on Saturday and now occupies its northwest. There is also fighting with the army in the city centre," said Rami Abdel Rahman of the Syrian Observatory for Human Rights.

IS took Palmyra in May last year, and systematically destroyed temples and tower tombs at the town's UNESCO World Heritage site, before being pushed out by government forces. 

But the militants have attempted to retrieve control of the city this week, with reports suggesting clashes between IS and Syrian regime forces on the outskirts of Palmyra, eight months after losing it.

The militant group has suffered major losses across swathes of territories it controls in Syria and Iraq, as the US-led global coalition continues its offensive to retake Raqqa and Mosul.

On Saturday, the White House said it will deploy 200 soldiers to assist in the battle against the Islamic State group.

Raqqa, which has also served as a hub for militants plotting attacks abroad, is being isolated according to a plan, US Defence Secretary Ashton Carter said.