Russia wants to conduct a joint bombing campaign against terrorist groups with the US-led coalition in Syria starting next week, Defence Minister Sergei Shoigu said Friday.
The campaign, which would begin Wednesday, should target al-Qaeda branch al-Nusra Front and other terrorists, as well as caravans supplying such groups with weaponry, Shoigu said, according to the TASS state news agency.
The US Defence Department said it had not received any such request from the Russians.
"We do not collaborate or coordinate on any operations in Syria," Pentagon spokesman Jeff Davis said, noting that the Russian focus is on supporting the Syrian regime, while the US is concentrated on defeating Islamic State.
Russia is a close ally of Syrian President Bashar al-Assad, while the US supports elements of the opposition. Moscow and Washington agree that certain terrorist groups in Syrian must be eliminated.
The powers helped broker a ceasefire in February in Syria that does not include UN-designated terrorist groups such as al-Nusra Front and rival Islamic State forces.
In Washington, White House spokesman Eric Schultz said that US defence cooperation with Russia on Syria was mainly focused on "de-confliction" to prevent accidental confrontations between their militaries.
Joint military actions are not a priority, he said.
"We believe that if Russia wants to do something to take on al-Nusra and [the Islamic State movement], the first thing on their to-do list is to make sure that the Assad regime is abiding by the cessation of hostilities in Syria," Schultz said.
"Clearly, the turmoil and chaos there is what provides a fertile breeding ground for [the Islamic State group] to conduct its operation. So, our goal is for Russia to urge its patron, Assad, to abide by the cessation of hostilities."