US president Barack Obama on Sunday urged Russia to stop bombing "moderate" rebels in Syria in support of its ally Bashar al-Assad, a campaign seen in the West as a major obstacle to the latest efforts to end the war.
Major powers agreed on Friday to a limited cessation of hostilities in Syria, but the deal does not take effect until the end of this week and was not signed by any of the warring parties – the Damascus government and numerous rebel factions fighting it.
Russian bombing raids directed at rebel groups are meanwhile helping the Syrian army to achieve what could be its biggest victory of the war in the battle for Aleppo, the country's largest city and commercial centre before the conflict.
There is little optimism that the deal reached in Munich will do much to end a war that has lasted five years and cost 250,000 lives.
The Kremlin said President Vladimir Putin and Mr Obama had spoken by telephone and agreed to intensify co-operation to implement the Munich agreement. But a Kremlin statement made clear Russia was committed to its campaign against Islamic State and "other terrorist organisations", an indication that it would also target groups in western Syria where jihadists such as al-Qaeda are fighting Mr Assad in close proximity to rebels deemed moderate by the West.
Russia says the “cessation” does not apply to its air strikes, which have shifted the balance of power towards Mr Assad.
Insurgent groups
It says Isis and the al-Qaeda-affiliated Nusra Front are the main targets of its air campaign. But western countries say Russia has in fact been mostly targeting other insurgent groups, including some they support.
The White House said Mr Obama's discussion with Mr Putin stressed the need to rush humanitarian aid to Syria and contain air strikes.
“In particular, President Obama emphasised the importance now of Russia playing a constructive role by ceasing its air campaign against moderate opposition forces in Syria,” the White House said in a statement.
Humanitarian aid
Relief workers said efforts to deliver humanitarian aid were being threatened by the latest escalation of violence.
“We must ask again, why wait a week for this urgently needed cessation of hostilities?” said Dalia al-Awqati, Mercy Corps director of programmes for north Syria.
The situation in Syria has been complicated by the involvement of Kurdish-backed combatants in the area north of Aleppo near the Turkish border, which has drawn a swift military response from artillery in Turkey.
Reaction from politicians in the West to the Munich deal was sceptical.
US senator John McCain said he did not view the deal as a breakthrough.
“Let’s be clear about what this agreement does. It allows Russia’s assault on Aleppo to continue for another week,” he said at a security conference in Munich.
“Mr Putin is not interested in being our partner. He wants to shore up the Assad regime,” Mr McCain said.
A senior ally of German chancellor Angela Merkel said Russia had gained the upper hand in Syria through armed force.
Norbert Roettgen, head of the foreign affairs committee in the German parliament, said Russia was determined to create "facts on the ground" to bolster its negotiating position.
Meanwhile, Saudi Arabia confirmed it had sent aircraft to Turkey's Incirlik air base to join the fight against Isis. – (Reuters)