BEIRUT: Kurdish-backed fighters on Tuesday announced they have agreed to a US-brokered ceasefire with Turkey in northern Syria for an unspecified period of time.

“We agreed on a ceasefire with the Turkish state via the United states and the international coalition” that is fighting the Islamic State group, said Ali Hajo, spokesman of the Jarablus Military Council.

Speaking to AFP by telephone, Hajo said the truce took effect at midnight and was expected to last “for an unspecified period of time”.

“We are continuing to negotiate (with the Turkish forces) through the Americans,” he said without elaborating.

The Syrian Observatory for Human Rights said it was calm on the southern front of Jarablus, which Turkish forces captured from IS jihadists last week on the first day of their incursion into Syria.

Hajo's comments came after a US defence official told AFP in Washington that Turkish and Kurdish forces in northern Syria had reached a “loose agreement” to stop fighting each other.

“In the last several hours, we have received assurance that all parties involved are going to stop shooting at each other and focus on the ISIL threat,” said Colonel John Thomas, Central Command spokesman.“It's a loose agreement for at least the next couple of days and we are hoping that will solidify,” he said.

Last week Turkey launched strikes at the Syrian Kurdish People's Protection Units (YPG) in northern Syria, triggering alarm bells in Washington.

The strikes and clashes that killed several Kurdish fighters at the weekend coincided with the launch of an operation in and around the border town of Jarablus.

The YPG fighters also operate in the area.

The Jarablus Military Council is backed by the Syrian Democratic Forces (SDF) alliance of Arab and Kurdish forces which this month drove IS militants out of Manbij, a town near the border with Turkey, with US air support.

On Monday, Turkey warned it would carry out more strikes on the US-backed YPG in Syria if it fails to retreat from the border area.

Ankara fears the emergence of an autonomous Kurdish region in Syria would bolster Kurdish rebels across the border in southeast Turkey.