ANKARA:- Turkish President Recep Tayyip Erdogan and Iranian counterpart Hassan Rouhani on Thursday vowed to work closer to end the fighting in Syriainfo-icon.But the two leaders made no comment on USinfo-icon President Donald Trumpinfo-icon's announcement that he was pulling US troops out of the warinfo-icon-ravaged nation, declaring a victory over the Islamic Stateinfo-icon of Iraqinfo-icon and the Levant (ISIL, also known as ISIS). 

Trump's decision signifies an end to the US air campaign against ISIL, US officials told Reuters, speaking on condition of anonymity.

Rouhani and Erdogan held a joint press conference after meeting each other in Ankara. 

"The fate of Syria should be determined only by the people of Syria. Everyone should respect Syria's territorial integrity and we (Iraninfo-icon and Turkeyinfo-icon) completely agree on this," Rouhani said.

Rouhani said Iran, Turkey and Russiainfo-icon will continue with the Astana negotiations on Syria's future, with the next summit to be held in Russia. Iran and Russia have provided crucial military aid to Syrian President Bashar al-Assad, while Turkey supports the opposition. 

Turkey, despite its differences with Iran and Russia over Syria, has worked closely with both countries to find a political solution to the war through the Astana process launched last year.

Turkey has recently warned that it will launch combat operations across its southern border into northeastern Syria against an alliance of Kurdish and Arab groups known as the Syrian Democratic Forces, or SDF, who have been allied with the US in the battle against the ISIL.

The US partnership with the SDF has outraged Ankara, which views the US-backed Kurdish People's Protection Units (YPG) as an extension of an armed group fighting inside Turkey.

US sanctions on Iran

Meanwhile, Rouhani thanked Erdogan for his support against Washington's "unilateral and illegal" sanctions.

"This US action against Iran is a 100-percent terrorist act," said Iran's president. 

In August, the US re-imposed a first round of sanctions that mainly targeted Iran's banking sector.

A second phase of sanctions - targeting Iran's energy sector - came into effect on November 5, although Washington granted a 180-day reprieve to the eight largest buyers of Iranian oilinfo-icon, including Turkey.

The leaders agreed on continuous cooperation in the areas of industry, transportation, energy, tourism and culture, Rouhani said.

For his part, Erdogan said Turkey and Iran should strengthen their bilateral relations to reach $30bn targeted bilateral trade volume.

He also said that the Turkey-Iran cooperation bore fruit during the Astana peace talks process with the participation of Russia.

"We need to increase our efforts to ensure permanent peace that will embrace Syria and whole Syrian people," he said.