US President Barack Obama has told world leaders that Syrian regime leader Bashar al-Assad must step down if the US-led coalition is to defeat the ISIS militant group.
Speaking on the sidelines at the UN General Assembly, Obama reportedly told world leaders that Syria requires a new leader in order to fight ISIS, which has taken advantage of the security vacuum arising from the civil war in the country to seize swathes of land there.
Obama’s briefing comes a year after the US-led coalition began targeting ISIS positions in Syria and Iraq. He told the world leaders that since airstrikes began, ISIS had lost control of a third of the populated areas it previously controlled and had almost been completely "cut off" from the borders of Turkey, a key member of the NATO military alliance.
However, Obama also warned that the coalition’s efforts to defeat ISIS would be unsuccessful unless the conditions that spurred the group’s ideology were addressed.
"This is not a conventional battle. This is a long-term campaign - not only against this particular network, but against its ideology," he said.
ISIS set up the de facto capital of its self-proclaimed state in the central Syrian city of Raqqa, from which it administers lands it seized both in Syria and Iraq.
The US has long called for Assad to step down, but after four-and-a-half-years of war which has killed around a quarter of a million people and displaced half of Syria’s population, Assad has refused to quit.
The past month, however, has seen the US softening its language against the Assad regime, which enjoys the backing of Russia and Iran.
According to the AFP news agency, Obama told world leaders during the meeting that the US was willing to cooperate with Russia and Iran to "find a political mechanism in which it is possible to begin a transition process."
US Secretary of State John Kerry also told MSNBC in an interview that the US could compromise with Russia and Iran if they convince Assad to stop dropping barrel bombs on civilians.
"They are both in a position, in exchange perhaps for something that we might do, they might decide to keep Assad from dropping barrel bombs," Kerry said.
Although Iran is not included in the US-led coalition, which includes over 60 countries, Iran and the US find themselves both backing the Iraqi government against ISIS, with the US providing aerial support to the Iraqi army and Iran equipping pro-government Shiite militias on the ground.
Talk of possible US-Russian coordination in Syria to fight ISIS is likewise ongoing, as Russia increases its military presence in the regime stronghold of Latakia in support of Assad's forces.
While Russia insists that Assad should be part of the solution process to end the conflict in Syria, the US believes keeping Assad in power will be counterproductive.
Earlier this month, however, Kerry reiterated the need for Assad to go, but at the same time insisted this did not necessarily have to be immediate.
"It doesn't have to be on day one or month one ... there is a process by which all the parties have to come together and reach an understanding of how this can best be achieved," he said.
Russian President Vladimir Putin avoided the UN General Assembly on Tuesday and instead sent a low-level Russian diplomat, but Russia is set to host a special UN Security Council meeting about terrorism on Wednesday.