US Defence Secretary, Jim Mattis, has appealed to Turkey to concentrate its fight in Syria against the Islamic State (IS) group as tensions mount between the two NATO allies over Ankara's operation against a Kurdish militia, the US Department of Defense (DoD) said on 15 February.

Mattis met with his Turkish counterpart Nurettin Canikli on 14 February on the sidelines of a NATO conference in Brussels.

During the talks, Mattis called ‘for a renewed focus on the campaign to defeat ISIS, and to preventing any vestige of the terrorist organisation from reconstituting in Syria,’ the US DoD said on 15 February, referring to the IS group.

Turkey in January launched an operation in northern Syria against a Kurdish militia, the Syrian People's Protection Units (YPG), which Ankara blacklists as a terror group but which is closely allied with the US in the battle against jihadists.

The operation has sparked a festering row between the two countries.

The US DoD said: ‘Mattis acknowledged the legitimate threats posed to Turkey's national security by terrorist organisations.

‘But he also discussed the complex security environment in Syria, and the danger that a resurgent ISIS could pose to all NATO allies.’

It said the two ‘agreed to continue their full range of bilateral and multilateral defence activities and consultations, and to look for ways to further strengthen defence cooperation in the future.’

The meeting came on the evening of a visit to Turkey by US Secretary of State Rex Tillerson.

During his two-day trip, Tillerson – who last visited in July 2017, will hold talks with his Turkish counterpart Mevlut Cavusoglu and President Recep Tayyip Erdogan.