Washington: Russian air strikes in and around the city of Aleppo against opponents of the Syrian regime are benefitting the Islamic State group, a senior US official charged on Wednesday.

‘What Russia’s doing is directly enabling ISIL,’ Brett McGurk, President Barack Obama’s special envoy to the coalition fighting the group in Syria and Iraq, told the House Foreign Affairs Committee.

US Secretary of State John Kerry has taken the lead over the past week in accusing Russia of derailing efforts to get Syrian peace talks going, by carrying out air strikes around Aleppo in support of a government offensive.

Kerry and some 20 foreign ministers, including Russia’s Sergei Lavrov, are meeting in Munich Thursday to try to arrange a ceasefire and humanitarian access to Syrian cities besieged by government forces.

‘We would have wanted a ceasefire two months ago and didn’t get it. We need one as soon as possible,’ a US diplomat, who asked not to be named, told reporters.

When asked if the Russians were on the same page, the diplomat said: ‘They say they are ... tomorrow is going be a moment where they are going to have to prove they are serious about this.’

On Tuesday, Kerry called on Moscow to work for an immediate ceasefire in Syria and to halt its air campaign, which has intensified in recent days.

The US-led coalition has waged a separate air campaign against IS since September 2014.

Russia, Syrian President Bashar al-Assad’s closest ally, began conducting air strikes of its own September 30, 2015, targeting mainly rebels backed by the West, according to US officials.

The State Department, asked about a possible ‘Plan B’ for Syria evoked by Kerry in an interview with the Washington Post, said there was a diplomatic process in place ‘that can work.’

‘I don’t think anybody’s ready to throw in the towel or to ... look at Plan B,’ spokesman Mark Toner said.

In his testimony, meanwhile, McGurk outlined coalition plans to intensify its campaign against IS in Iraq and Syria, acknowledging the complexity of the task because it relies heavily on a diverse array of local forces on the ground.

‘This is extremely difficult, but now doable. Our progress will not always be linear, and we should expect setbacks and surprises,’ McGurk said in his written testimony.