Russian President Vladimir Putin's invasion of Ukraine has been backed by Iran, with its Supreme Leader claiming the West opposes an "independent and strong" Russia.
Iranian leader Ali Khamenei said Russia faced an attack from the NATO military alliance if it hadn't sent troops into Ukraine, mirroring Mr Putin's own justification for the war.
His statement reflected increasingly close ties between Moscow and Tehran amid heavy Western sanctions on both countries.
Mr Putin met with Iranian President Ebrahim Raisi and Turkish President Recep Tayyip Erdogan to talk Syria and a UN-backed proposal to export Ukrainian grain.
It was his second trip abroad since Russian troops entered Ukraine in February.
NATO member Turkey has faced off against Russia previously in Syria and Libya, and has also sold lethal drones to Ukrainian forces, but has not imposed sanctions.
Mr Putin thanked Mr Erdogan for his help to "move forward" the grain deal.
"Not all the issues have been resolved yet, but it's good that there has been some progress," Mr Putin said.
Mr Erdogan praised what he described as Russia's "very, very positive approach" during last week's grain talks in Istanbul, adding he hoped a deal would "have a positive impact on the whole world".
The trip to Tehran had symbolic meaning for Mr Putin as well, emphasising Russia's international presence even as it became more isolated and deeper in conflict with the West.
It also came just days after US President Joe Biden visited Israel and Saudi Arabia, Tehran's primary rivals.
From Jerusalem and Jeddah, Biden urged Israel and Arab countries to push back on Russian, Chinese and Iranian influence that has expanded with the perception of America's retreat from the region.
All countries have agreed on drawing closer to counter Iran and its rapidly advancing nuclear program. Negotiations with Iran have deadlocked.
The Iranian government has ramped up uranium enrichment, cracking down on dissent and grabbing optimistic headlines.
Without sanctions relief in sight, Iran's tactical partnership with Russia has become one of survival.
"Iran is (the) centre of dynamic diplomacy," Iranian Foreign Minister Hossein Amirabdollahian wrote on Twitter, adding the meetings would "develop economic cooperation, focus on security of the region … and ensure food security".
Fadahossein Maleki, a member of the Iran's committee on national security and foreign policy, described Russia as Iran's "most strategic partner" despite years of animosity between the two.
The US claimed Russian officials recently visited an Iranian airfield at least twice to see Tehran's weapons-capable drones.
Mr Putin said the two countries have worked to "strengthen their cooperation on international security" and offered support to Tehran on the deadlocked nuclear deal.
Mr Erdogan focused on Turkey pushing back US-backed Syrian Kurdish fighters from its borders, part of its plan to create a safe zone along the Turkish-Syrian border.
He said Turkey was determined to "drive out the centres of evil" that targeted Turkey's security.
"The greatest favour that would be made to the Syrian people would be the complete removal of the separatist terrorist organisation from territories that it occupies," Mr Erdogan said.
The three presidents in a joint statement said they "rejected all attempts to create new realities on the ground under the pretext of combating terrorism, including illegitimate self-rule initiatives, and expressed their determination to stand against separatist agendas".
However, Mr Khamenei in a meeting with Mr Erdogan sternly warned against the planned Turkish incursion.
"Any sort of military attack in northern Syria will definitely harm Turkey, Syria and the entire region, and will benefit terrorists," he said, stressing the need to "bring the issue to an end through talks".
Humanitarian issues in Syria have also come into focus since Russia vetoed aid deliveries to 4.1 million people in Syria's rebel-held north-west, forcing them to stop after just six months.
All parties urged expelling American forces from Syria, with Mr Putin denouncing what he claimed was the US military's "attempts to cement unlawful foreign military presence and ferment separatist sentiments".
ABC/AP
