PHOTO: Aftermath of a Russian-regime airstrike on Bab al-Nairab in Aleppo Province, August 27, 2016 (Abdalrhman Ismail/Reuters)

Russia has stepped back from a temporary ceasefire arrangement for Syria’s largest city Aleppo, as it steps up bombing of rebels to help the recovery of the Assad regime’s military position.

US officials said early on Sunday that a deal was close, even though President Obama cautioned, “We’re not there yet” on “a very complicated piece of business”. (see separate entry).

But a “senior State Department official”, accompanying Obama in China at the G20 summit, later said, “Russians walked back on some of the areas we thought we were agreed on, so we are going back to capitals to consult.”

He said US Secretary of State John Kerry and Russian Foreign Minister Sergei Lavrov will meet again on Monday on the sidelines of the summit.

Kerry told reporters:

We’re going to review some ideas tonight, a couple things on these couple of tough issues, and come back together and see where we are.

We’re not going to rush.

But observers suggested that Russia had pulled back from the plan, for 48-hour ceasefires to allow aid into parts of Aleppo, because it first wanted to ensure a recovery of the regime’s position near the city.

Over the weekend, Russia stepped up intensive airstrikes on areas captured by rebels southwest of Aleppo in an offensive earlier this month.

Enabled by the strikes, the Syrian military and foreign allies such as Hezbollah retook an air force college and large artillery base on Sunday.

See Syria Daily, Sept 4: Aleppo Front — Pro-Assad Forces Regain Artillery Base

Russia and the Assad regime are trying to close the Ramouseh corridor, which rebels opened in their offensive in early August. While the corridor was not secure, it was symbolic in breaking the siege of opposition areas of Aleppo, established by Russia, the Syrian military, and foreign forces a month earlier.

Russia has proposed that aid be allowed only through the al-Castello Road, the route north of Aleppo seized in early July. The Syrian opposition and rebels have insisted that the Ramouseh corridor be used to ensure that opposition districts receive assistance.

Russian-regime attacks on the air force college and artillery base:

Head of UN Humanitarian Operations in Iran for Talks

Meanwhile, as Russia and the Assad regime effectively re-imposed the siege on Aleppo, the head of UN humanitarian operations is visiting President Assad’s other major backer, Iran.

Stephen O’Brien met Interior Minister Abdolreza Rahmani Fazli about “the enhancement of cooperation among regional countries in humanitarian missions”.

O'BRIEN IN IRAN 04-09-16

Iran’s Press TV declares, “O’Brien’s trip to Tehran could be an opportunity to draw attention to the Islamic Republic’s considerable experience and expertise in disaster management and humanitarian response.”

The article makes no mention of Iran’s prominent involvement on the battlefield near Aleppo, through its commanders, troops, and Iranian-led foreign militias.

However, the Supreme Leader’s top aide, Ali Akbar Velayati, made clear after meeting O’Brien that Iran’s priority is support of the Assad regime.

“Experience has shown that the Iranian people never gets exhausted with supporting the resistance groups,” Velayati said.