The European Union (EU) foreign policy chief has cautioned against the risk of a war with active military hostilities between Turkey and Russia over Syria, where regional powers have sided with warring sides to the conflict gripping the Arab country.

Federica Mogherini issued the warning during a debate at the European Parliament's Foreign Affairs Committee in the Belgian capital city of Brussels on Tuesday.

"We are always referring to Syria as a proxy war among regional actors,” Mogherini said, adding, however, that the current situation in Syria risks becoming “something bigger”.

“I'm not thinking of a cold war. No, we risk a hot war among different actors than the one we always think of. Not necessarily Russia and the United States, but Russia and Turkey, could be,” she said.

Russia launched its own anti-terror campaign in Syria on September 30, 2015, upon a request from the Damascus government. The airstrikes have expedited the advances of Syrian forces against militants.

On the contrary, Turkey is among the main supporters of militants fighting to topple Syrian President Bashar al-Assad. Ankara has also been accused on numerous occasions of being involved in illegal oil trade with the Takfiri Daesh terrorist group.

All sides to Syria conflict should respect truce

In another development on Tuesday, the Arab League urged all sides to the conflict in Syria to adhere to the terms of a ceasefire deal announced by the United States and Russia the previous day.

Arab League Secretary General Nabil Elaraby ©AP

The 22-member body said in a statement that Arab League Secretary General Nabil Elaraby believes that the truce will be "an important step towards a political settlement of the Syrian crisis."

On Monday, Washington and Moscow said the ceasefire has been planned to take effect in Syria on February 27.

Over the past few weeks, Syrian government forces, backed by Russia’s air cover, have managed to gain major positions from the foreign-backed militants.