The use of chemical weapons and the involvement of Hezbollah fighters in the conflict in Syria is threatening to put a political settlement out of reach.

That’s according to the US Secretary of State John Kerry whose department issued a statement to that effect after he spoke to Iraq’s foreign minister.

But Russia believes it is action by the US which is endangering any settlement. President Barack Obama and his Russian counterpart, Vladimir Putin, are due to discuss Syria at next weeks G8 summit. On Saturday there was a warning to Washington over plans to enforce a no-fly zone over Syria.

“You don’t have to be a great expert to understand that this will still violate international law, and we really hope that our American colleagues will align their actions in accordance with the approach of the Russian-American initiative in preparation for the conference on Syria,” said Russian Foreign Minister Sergei Lavrov.

A no-fly zone would be enforced from Jordan. The Pentagon said on Saturday the US has agreed to keep Patriot missile batteries and F-16 fighter jets in Jordan after joint military exercises end this month amid the crisis in Syria.