TEHRAN: Iran, Russia and Turkey, which support opposing sides in Syria's war, agreed Wednesday to coordinate their efforts to reduce tensions in the country, whose conflict has entered its 10th year.

The three "reiterated their determination to enhance the trilateral coordination", said a joint statement issued at the end of a video conference between their leaders.

The declaration also "emphasised their strong commitment to the sovereignty, independence, unity and territorial integrity" of Syria.

The talks were the first since September in the so-called Astana format, talks between the three main foreign powers in the Syrian conflict.

Iran and Russia have been staunch supporters of President Bashar al-Assad, while Turkey has called for the ouster of his regime and backed opposition armed groups.

The conference comes at a time when Russia-Turkey relations are tense not just over Syria but also Libya, another theatre of war where Moscow and Ankara support opposing fighters.

But Iran's Foreign Minister Mohammad Javad Zarif, whose country chaired the online meeting, described the talks as "constructive".

The three countries had "agreed to continue coordination... focusing on tension reduction, political process and humanitarian relief," he tweeted.

Iran's President Hassan Rouhani told the conference "the Islamic republic believes the only solution to the Syrian crisis is political and not a military solution."