In this photo released by the Syrian official news agency SANA, Syrian President Bashar Assad, right, meets with Alaeddin Boroujerdi, the Iranian head of an influential parliamentary committee on national security and foreign policy, left, in Damascus, Syria, Thursday, Oct. 15, 2015. Boroujerdi reiterated his country鈥檚 full support for the Syrian government, stressing that a political solution is the only way for Syria to emerge from the current crisis. Boroujerdi鈥檚 comments came a day after a regional official said hundreds of Iranian troops are being deployed in northern and central Syria, dramatically escalating Tehran鈥檚 involvement in the civil war as they join allied Hezbollah fighters in an ambitious offensive to wrest key areas from rebels amid Russian airstrikes. AP FILE PHOTO
MOSCOW, Russia鈥擨ran said Wednesday it will take part for the first time in international talks aimed at resolving the brutal war in Syria, as a diplomatic push to end the conflict gained momentum.
READ: US officials: Iran invited to next round of Syria talks
Iran鈥檚 Foreign Minister Javad Zarif will join key players in the Syria crisis鈥攊ncluding Russia, the United States and Saudi Arabia鈥攊n Vienna on Friday for a renewed effort to end more than four years of bloodshed.
US Secretary of State John Kerry cautioned that this week鈥檚 talks would not secure an immediate political solution, but nevertheless represented the best hope available.
鈥淲hile finding a way forward on Syria will not be easy鈥攊t鈥檚 not going to be automatic鈥攊t is the most promising opportunity for a political opening we have seen,鈥� Kerry said just before he was to set off for Vienna.
鈥淭he challenge that we face in Syria today is nothing less than to chart a course out of hell,鈥� he added.
Washington is at loggerheads with Moscow over Syria, accusing Russian forces of concentrating their air campaign there on moderate opposition groups opposed to Syrian President Bashar al-Assad鈥檚 rule.
Moscow says its bombing campaign is targeting Islamic State jihadists and also other 鈥渢errorist鈥� groups.
But Kerry stressed that the US and Russia also shared 鈥渃ommon ground,鈥� arguing that both want 鈥渁 united, secular Syria鈥� in which citizens can choose their own leader through elections.
READ: Iran sends fighters to Syria, escalating its involvement
The inclusion of Iran鈥攁 key ally of Assad鈥攊n this week鈥檚 meetings marks a crucial shift after Tehran was excluded from earlier talks, mainly because of opposition from Washington and Riyadh.
鈥淲e have reviewed the invitation, and it was decided that the foreign minister would attend the talks,鈥� Iranian foreign ministry spokeswoman Marzieh Afkham said.
It will be the first time all the major international players in the conflict are in the same room, but there has been no mention of either the Syrian government or the opposition attending.
Divisions over Assad鈥檚 future
Top diplomats from Russia, the United States, Saudi Arabia and Turkey will also meet beforehand on Thursday evening, the second time the quartet will have met in less than a week.
The following day will see them joined by Britain, Egypt, France, Germany, Italy, Lebanon and the European Union.
Britain鈥檚 Foreign Office said the United Arab Emirates, Qatar, and Jordan will also be present.
After months of failure, efforts to find a breakthrough have gained聽pace as hundreds of thousands of Syrians have fled their shattered country.
Serious divisions remain over when or whether Assad should step down鈥攁nd four-way Russia-US-Saudi-Turkey talks in Vienna last Friday failed to make a breakthrough.
On one side, Russia and Iran are backing Assad鈥檚 forces on the ground and say Damascus must be helped to defeat 鈥渢errorism鈥� before a political process can take shape.
On the other, the United States and its key regional allies Turkey and Saudi Arabia are supporting groups fighting Assad and insist he must go.
French Foreign Minister Laurent Fabius said Wednesday that France and its allies had agreed on the need for a 鈥減recise timetable鈥� for Assad鈥檚 departure.
But Kremlin spokesman Dmitry Peskov said it was impossible to discuss the details of a political solution before delivering 鈥渢he final blow to terrorists.鈥�
鈥淚t would be absolutely illogical to act otherwise,鈥� he was quoted as saying by Russian news agencies.
Meanwhile, the Pentagon announced plans to step up attacks on Islamic State jihadists in Syria and Iraq, with Defense Secretary Ashton Carter saying he expected more airstrikes and even possible 鈥渄irect action on the ground.鈥�
鈥楽tuck in quagmire鈥�
The dynamic in the Syrian conflict shifted after Russia launched its air campaign on September 30, claiming it was targeting IS fighters.
Russian warplanes have struck 118 鈥渢errorist鈥� targets in Syria over the past 24 hours鈥攖he highest total yet鈥攖he defense ministry in Moscow said Wednesday.
Iran is believed to have sent thousands of troops and Hezbollah militia fighters to support Assad鈥檚 forces.
But the US believes they will struggle to defend Assad for long, which is why they have been forced to engage diplomatically.
More than 250,000 people have been killed in Syria鈥檚 brutal conflict since it began in March 2011 following a bloody crackdown on protests against Assad鈥檚 rule.
Doctors Without Borders (MSF) said Thursday a 鈥渟ignificant increase鈥� in air strikes on Syrian hospitals since late September has killed at least 35 patients and medical staff and wounded 72.
鈥淎fter more than four years of war, I remain flabbergasted at how international humanitarian law can be so easily flouted by all parties to this conflict,鈥� said Sylvain Groulx, MSF chief for Syria.