Turkey's president has criticised delays in the US-led coalition's fight against the Islamic State group in Syria and Iraq, as the extremists pressed ahead with an offensive against Syrian government forces.
Speaking in Ankara on Tuesday, Recep Tayyip Erdogan said "the operations that are constantly delayed are of no benefit for the well-being of these two countries' people".
He spoke after the capture of an Uzbekistan national who authorities say trained in Afghanistan and carried out a deadly New Year's nightclub attack in Istanbul.
Turkey is a partner in the US-led coalition against IS, which claimed the attack.
The extremist group said it was a reprisal for Turkey's campaign to dislodge the militants from the northern Syrian town of al-Bab.
Turkey, which for years supported the Syrian opposition drive to oust President Bashar Assad, has recalibrated its priorities towards fighting Islamic State militants and thwarting Kurdish aspirations for autonomous rule along Syria's border with Turkey.
Turkish troops rolled over the border in August to help Syrian opposition forces battle IS and halt the advance of US-backed Syrian Kurdish fighters, who are also fighting the extremists.
However, nearly two months into the assault on al-Bab, one of Islamic State's last major strongholds in northern Syria, Turkey has become bogged down in the fighting, which has driven a wedge between Ankara and Washington.
Turkish officials say Washington has not done enough to support Turkey's operations in al-Bab and has forced Ankara to reach out to Russia for aerial support.
Meanwhile, in Syria's eastern city of Deir el-Zour, fighting between Syrian government forces and Islamic State militants continued for the fourth day on Tuesday.
IS fighters launched a new offensive to try and capture government-controlled parts of the contested city, also attacking a nearby military air base from several fronts.
On Monday, the group made substantial gains near the air base, cutting the government-controlled pocket in half and further tightening the two-year-old siege on parts of the city.
The extremist group, which controls most of Deir el-Zour province, has kept the provincial capital under siege since 2014. The new multi-pronged assault that began on Saturday is its most intense attack on government areas in a year.
Government forces have withstood the encirclement thanks to air-dropped humanitarian assistance and weapons and ammunition flown into the airport.
Remaining residents have reported malnourishment and starvation amid severe shortages of food, water and fuel.
The Britain-based Syrian Observatory for Human Rights said 122 people have been killed in and around the city, including 27 civilians.
That number could not be independently verified.