ERBIL, Kurdistan Region - A potential Turkish operation in northern Syria will definitely harm all parties involved and the region, Iran's supreme leader told the Turkish president on Friday, as he called for Syria's sovereignty to be respected.

In a Tehran meeting with Turkish President Recep Tayyip Erdogan, Iran's Supreme Leader Ayatollah Ali Khamenei called Ankara's looming offensive on northern Syria detrimental to both Syria and Turkey, adding that the operation will not achieve the expected political results from the Syrian government.

Erdogan arrived in Tehran on Monday and is expected to partake in a trilateral summit with the presidents of Iran and Russia – Ebrahim Raisi and Vladimir Putin – with the main focus of the meeting expected to be ostensibly based around the conflict in Syria as part of the Astana peace process with the country in its eleventh year of a brutal civil war.

As opposed to an operation, Khamenei instead called for utilizing dialogue to put an end to the conflict.

In late May, Erdogan said his country is planning to embark on yet another military operation in northern Syria, aimed at expelling Kurdish fighters of the US-backed People's Protection Units (YPG), which Ankara considers to be the Syrian offshoot of the Kurdistan Workers' Party (PKK) from the region.

Both the YPG and the PKK are designated as terrorists by Ankara, who has launched successive operations in Syria to clear swathes of territory from the former, with the next planned offensive directed at the areas of Manbij and Tal Rifaat – areas where Turkey believes the presence of YPG fighters threatens its national security.

Iran, Russia, and Turkey have taken opposing sides in the Syrian conflict, with Tehran and Moscow backing the government of Syrian President Bashar al-Assad in his quest to crush rebels in the war-torn country and Ankara backing rebel militias in Syria's north.

Terrorism must be opposed, but a military attack in Syria will benefit terrorists, although terrorists are not limited to a specific group, Khamenei told Erdogan, giving unclear signals over whether Tehran and Ankara regard the same groups as terrorists.

However, the Iranian leader told Turkey his country will certainly cooperate in the fight against terrorism in response to Erodgan requesting Iranian support.

Iran has previously warned that any kind of military operation in northern Syria will cause regional instability.

Erdogan also expressed support for Iran's legitimate expectations in reviving the stalled nuclear deal, known as the Joint Comprehensive Plan of Action (JCPOA), further encouraging Turkish companies to invest in Iran.

Iran and world powers, including the US, have held talks for over a year aimed at reviving the 2015 landmark nuclear accord. The Islamic republic has demanded that the US must lift its crippling sanctions, including those on the Islamic Revolutionary Guard Cops (IRGC), which Washington has placed on a terror blacklist.[1]