London: US Secretary of State John Kerry on Saturday said Russia and Iran could help facilitate Syrian President Bashar al-Assad's departure from power and ensure a political transition in the Middle East nation.
He made the remarks after meeting Britain's foreign secretary Philip Hammond to discuss the war in Syria that has "gone on too long" and caused a humanitarian catastrophe.
The US secretary of state said Washington was flexible with regard to the time frame for Assad's departure, adding that it does not have to occur "on day one, or month one, or whatever".
Hammond said for his part that the US and Britain were "completely aligned" on the need for Assad to step down and also said the timing and conditions of his exit need to be discussed.
Kerry also pledged to provide additional support to Europe and help mitigate the effects of the migrant crisis, saying the "root cause" of the exodus must be addressed.
That was a clear reference to Syria, whose conflict has produced millions of refugees, many of whom have been fleeing to Europe after taking refuge in countries such as Lebanon, Turkey and Jordan.
"We're committed to try to do more and we're looking at exactly what it will take to do more," Kerry said, noting that the US has already contributed $4.1 billion in assistance for the asylum seekers from Syria and other war-torn countries.
He said Russia now appeared more committed to struggle against the Islamic State and that it could be the time to reach a political solution.
Hammond, however, said the Syrian crisis was becoming "more complicated" by Russia's increased military engagement in the country in recent weeks in support of Assad.
"I think we need to discuss this as part of a much bigger problem - the migration pressures, the humanitarian crisis in Syria, as well as the need to defeat (IS)," the British foreign secretary said.
The US secretary of state said all of those issues would continue to be discussed in New York at the UN General Assembly meeting scheduled for later this month.
Kerry will travel on Sunday to Berlin to meet his German counterpart Frank-Walter Steinmeier to discuss the possibility of Russia playing a constructive diplomatic role in finding a solution to the Syrian conflict.