WASHINGTON - Iranian Foreign Minister Mohammad Javad Zarif will attend talks in Vienna over the Syrian civil war this week, joining the United States, Russia and other nations.

“We have reviewed the invitation, and it was decided that the foreign minister would attend the talks,” Iranian foreign ministry spokeswoman Marzieh Afkham was quoted as saying in media reports.

Foreign ministers from Saudi Arabia, Turkey, Iraq and Egypt also are scheduled to attend the meetings set for Thursday and Friday.

It will be the first time Secretary of State John Kerry will enter in negotiations with Tehran on matters other than the nuclear agreement reached in July, according to The New York Times.

Russia, an ally to Syrian President Bashar al-Assad, has continuously stated that Iran, another Assad ally, needs to be involved in talks that hope to create a political solution to the Syrian conflict. The United States has criticized Iran’s activities in Syria, but State Department spokesman John Kirby on Tuesday said Iran’s entry into the discussion was needed.

The United States has “recognized that at some point in the discussion, moving toward a political transition, we have to have a conversation and a dialogue with Iran,” Kirby said.

More than 250,000 people have died and more than 11 million have been displaced by the Syrian civil war. A US-led coalition has carried out more than 7,000 airstrikes against Islamic State targets in Syria and Iraq for more than a year.

“We have reviewed the invitation, and it was decided that the foreign minister would attend the talks,” Iranian foreign ministry spokeswoman Marzieh Afkham said. The talks Friday will follow a meeting between the top diplomats of Russia, the United States, Saudi Arabia and Turkey on Thursday evening, the second time the quartet will have met in less than a week.

Britain, Egypt, France, Germany, Lebanon and the European Union all confirmed they would take part, with Britain’s Foreign Office saying the United Arab Emirates, Qatar, Jordan and Italy would also attend. There was no mention of either the Syrian government or the opposition attending.

After years of international failure to stem the violence in Syria, the talks in Vienna will be the first time all major international players in the conflict will be in the same room.

Serious divisions remain over when or whether Assad should step down - and the four-way Russia-US-Saudi-Turkey meeting last Friday in the Austrian capital failed to make a major breakthrough.

On one side are Russia and Iran, which are backing Assad’s forces on the ground and say Damascus must be helped to defeat “terrorism” before a political process can start.

On the other are the United States and its key regional allies Turkey and Saudi Arabia, which are supporting groups fighting Assad and insist he must go if there is to be any hope of peace.

French Foreign Minister Laurent Fabius said Wednesday that France and its allies had agreed on the need for a “precise timetable” for Assad’s departure.

“We worked on the details of a political transition guaranteeing the departure of Bashar al-Assad within a precise timetable,” he said after talks late Tuesday in Paris with officials from the US, Britain, Germany, Italy, Saudi Arabia, Turkey, Jordan, Qatar and the United Arab Emirates.

US State Department spokesman John Kirby said Tuesday that he doubted the upcoming round of talks in Vienna would be “the last chapter”.

But Kirby said Secretary of State John Kerry felt “progress was being made towards laying down the foundation of what a political transition could look like”.

At the same time the Pentagon announced plans to step up attacks on Islamic State jihadists operating in both Syria and Iraq, with Defense Secretary Ashton Carter saying he expected more airstrikes and even possible “direct action on the ground”.

The dynamic in the Syrian conflict shifted after Russia launched an air campaign in support of Assad’s forces on September 30 - allowing Syrian troops to go back on the offensive and overshadowing a US-led coalition bombing Islamic State jihadists.

Assad then made a surprise visit to Moscow last week - his first known foreign trip outside Syria since the conflict began.

Russia says its bombing campaign is targeting IS fighters and other “terrorist” groups but Washington and its allies insist that Moscow is hitting more moderate groups battling Assad.

Russian warplanes have struck 118 “terrorist” targets in Syria over the past 24 hours - the highest total yet - the defence ministry said Wednesday, attributing the rise to new surveillance data.

Russian jets hit targets in the provinces of Idlib, Homs, Hama, Aleppo, Damascus and Latakia, a spokesman said.

Iran meanwhile is believed to have sent fighters to back up Assad on the ground. Several thousand Iranians and allied fighters from Lebanon’s pro-Iranian Hezbollah militia are believed to be fighting alongside Assad’s forces.

More than 250,000 people have been killed since Syria’s brutal conflict broke out in March 2011, sparked by a bloody crackdown on protests against Assad’s rule.

Assad on Wednesday renewed his accusation that Western states including France were supporting “terrorist” groups in his country.

“Several countries in the region and the West, including France, are continuing up until now to support terrorism by giving political cover to terrorist groups in Syria and the region,” he told three visiting French right-wing legislators, according to state news agency SANA.

Assad said terrorism was “the main cause of the suffering of the Syrian people” and warned it was “an international phenomenon which no border can prevent from spreading”.