Iranian Foreign Minister Mohammad Javad Zarif and his deputies will attend talks on the war in Syria held in Vienna, the semi-official ISNA news agency reported.

"We have reviewed the invitation, and it was decided that the foreign minister would attend the talks," foreign ministry spokeswoman Marzieh Afkham said on Wednesday. 

"Deputy Foreign Ministers Hossein Amir Abdollahian, Abbas Araqchi and Majid Takht Ravanchi will accompany Zarif on this trip."

Inside Story: Can Tehran deliver a solution on Syria?

The meeting is set for Friday in the Austrian capital.

On Tuesday, the US state department said that Tehran, a key ally of Damascus, would be invited to participate in the talks.

In an interview with Al Jazeera, Iranian journalist Ghanbar Naderi said the increasing number of deaths of Iranian soldiers in Syria may have prompted Tehran to join the negotiations. 

"The soldiers in Syria are not normal people, they are the top commanders from the IRGC and [Iranian] elite forces," he said.  

"Losing these key people in Syria, it is definitely under pressure. I think if Iran is accepting the dialogue, to now sit next to the international community, to find a way out of the Syrian crisis by dialogue and politics, I think it's because it doesn't want to lose any more commanders."

Tehran officially denies it has combat troops in Syria. But there have been reports that 18 high-ranking officers have been killed in Syria in the last three years.

Iran has also spent billions of dollars in the past four years to keep Syrian President Bashar al-Assad in power, with hundreds of its troops on the ground.

Across the border, Iran maintains strong links with Shia armed groups in Iraq, known as the Popular Mobilisation Units.

And Iran's relationship with Russia is growing stronger, with the two nations setting up a joint intelligence centre in Baghdad, to work with Syrian and Iraqi forces.

Renad Mansour, a visiting scholar at the Carnegie Middle East Center in Beirut, said dialogue with Iran is essential to end the war in Syria.

"Iran has now accomplished the nuclear issue, which was the top priority and now they're moving on. And Iran isn't happy with the situation in Syria. It wants to move away from being a pariah."

Source: Al Jazeera and agencies