Iranian Foreign Minister Mohammad Javad Zarif was in Damascus on September 3 for talks with President Bashar al-Assad and other Syrian officials ahead of an expected military offensive by Syrian government forces in Idlib Province, the last opposition stronghold in Syria.
The visit also comes days before a summit between the leaders of Russia, Iran, and Turkey to discuss the Syrian conflict, now in its eighth year.
During their meeting, Zarif and Assad "asserted that the pressures from some Western states on Syria and Tehran will not deter the two countries from continuing to defend their principles," the Syrian president's office said in a statement.
Zarif earlier met with his Syrian counterpart, Foreign Minister Walid al-Muallem, to discuss political and military developments "in preparation for the tripartite summit," according to Syria's Foreign Ministry.
"They shared identical views on the importance of strengthening bilateral coordination and political discussions in the coming phase," a statement said.
Zarif also held talks with Syrian Prime Minister Imad Khamis, who told Iran's minister that Syria's reconstruction plans would be carried out with the help of Iranian and Russian companies, Iran's semiofficial Fars news agency reported.
Backed by Russia and Iran, Assad has vowed to defeat the opposition fighters in Idlib if they do not surrender to Syrian government rule.
Fars quoted Zarif as saying in Damascus that "the remaining terrorists in the remaining parts of Idlib must be cleaned out and the region should be placed back under the control of the Syrian people."
Russian Foreign Minister Sergei Lavrov said in Moscow on September 3 that Syrian government forces had the right to "liquidate terrorists" in Idlib.
Syrian, Russian, and Iranian officials often refer to any armed opponent of the Damascus government as a "terrorist."
But U.S. Secretary of State Mike Pompeo said on August 31 that Washington would consider an assault in Idlib by Assad's forces as an escalation of Syria's war.
The State Department has also warned that Washington would respond to any chemical attack carried out by Syrian government forces.
With some 3 million people now living in Idlib and the surrounding area, United Nations officials have warned that a government offensive could displace 800,000 people.
The Kremlin on September 3 confirmed that Russian President Vladimir Putin would travel to Tehran on September 7 for talks with the leaders of Iran and Turkey about the situation in Syria.
Zarif said in Damascus that those talks also would focus on the battle against remaining militant groups that are fighting government forces in Syria.
Zarif said the talks would be "a continuation of the three-way political round" that examines "the methods of how to confront extremist and terrorist groups, like Tahrir al-Sham."
Tahrir al-Sham, which includes the Al-Qaeda-linked group formerly known as the Al-Nusra Front, is the most powerful militant alliance in Idlib Province.
Last week, Iran's defense minister travelled to Damascus and signed an agreement on military cooperation between the two countries.