A senior Iranian official says a "triangle" plot carried out by the US, Israel and their regional allies to oust the Syrian government has become "abortive" after 85 months.

Yahya Rahim Safavi, a top military adviser to Leader of the Islamic Revolution Ayatollah Seyyed Ali Khamenei, also said Sunday he was hopeful that the Syrian army and its popular allies would evict US troops from east of the Euphrates river.

"From the very beginning, the major objective of the Americans, the Zionist regime, the European Union, Saudi Arabia, the United Arab Emirates, Jordan and Turkey was to create a crisis in the region and target Syria's independence, national identity and territorial integrity and destroy its infrastructure, but they suffered maximum defeat," he said.

The US has deployed troops to Syria without the Arab country's consent and a UN mandate, setting up a string of military bases which have turned to safe havens for militants fighting to topple the Syrian government.

US support for Kurdish militants in Syria has worried its traditional ally Turkey, which has launched an offensive to push the fighters back from the areas close to its borders.

Major General Safavi, who was the former chief of the Islamic Revolution Guards Corps (IRGC), said US strategy was based on force but the policy has failed in West Asia.

The general hailed Ayatollah Khamenei, saying his "strategic measures paved the way for Russia to come to the Syria theater and provide good aerial support in the operations to liberate cities."

With the tide of the war having turned in Syria's favor, "the Syrian army and the resistance axis must continue their victorious operations, but in my view, the resistance government of Mr. Bashar Assad should also pursue a political solution in parallel with the armed struggle of the Syrian army and people," he said.

Safavi further praised Iran's military assistance to Syria and its missile attack on Daesh headquarters in the country last year.

He said the missiles precisely found their targets thanks to coordinates provided by IRGC drones which flew at night and staked out the structures. "This shows the high precision and power of our missiles."

The handout picture provided by IRIB on June 18, 2017 shows Iran’s Islamic Revolution Guards Corps (IRGC) launching a missile from an undisclosed location in western Iran, towards Daesh terrorists in Syria. (Via AFP)

On June 18, 2017, Iranian missiles hit Daesh headquarters in Syria’s Dayr al-Zawr province in the first such attack on targets outside Iran, in which more than 170 Takfiri elements were killed and their heavy weapons and communication equipment destroyed.

The missile attack came in response to a terrorist assault on June 7 when Daesh terrorists opened fire at ordinary people in Tehran, leaving 18 people dead and over 50 others wounded.