US and Western diplomats scrambled to cobble together a diplomatic strategy to end the war in Syria, after the latest humiliating blow to their military plan.
Secretary of State John Kerry and his European counterparts reached out to traditional foe Iran on the sidelines of the UN General Assembly in New York.
Iran and Russia back Syrian strongman Bashar al-Assad, whom Washington sees as the instigator of the civil war that left half his country in the hands of the Islamic State group.
Unwilling to countenance a peace process that would leave Assad in power after he alienated or killed so many of his people, the US has backed small “moderate” rebel groups.
But that strategy appeared in tatters on Saturday after the Pentagon admitted the latest US-trained fighters to cross into Syria had given a quarter of their gear to al-Qaeda.
A previous 54-strong group that crossed into Syria earlier this year was attacked by al-Qaeda’s local franchise, the al-Nusra Front, and fell apart, leaving only four or five guerrillas active.
With the initiative falling away, Kerry and his allies came to New York hoping to persuade Tehran and Moscow to push for a broad political solution to the conflict.
On Friday, the Pentagon admitted a 70-strong group of rebels that it had trained to fight the Islamic State as part of a $500m programme had surrendered much of its equipment, including vehicles and munitions, to the al-Nusra Front.
US Central Command, which oversees the fight against the IS group, is also facing an investigation into reports it had manipulated intelligence reports to paint a rosier picture of the campaign.
Meanwhile, Russian President Vladimir Putin on Sunday branded US support for rebel forces in Syria as illegal and ineffective, saying US-trained rebels were leaving to join Islamic State with weapons supplied by Washington.
In an interview with US networks recorded ahead of a meeting with his US counterpart Barack Obama, Putin said Syrian President Bashar al-Assad deserved international support as he was fighting terrorist organisations.
“In my opinion, provision of military support to illegal structures runs counter to the principles of modern international law and the United Nations Charter,” he said in an excerpt of an interview with US television networks CBS and PBS released by the Kremlin.
Russia has stepped up its military involvement in Syria in recent weeks, with US officials accusing Moscow of sending combat aircraft, tanks and other equipment to help the Syrian army.
Conservative British newspaper The Sunday Telegraph reported that UK Prime Minister David Cameron is open to keeping Syrian President Bashar al-Assad in power in the short term while a unity government is formed in the country.
Citing an unnamed high-level government source, the newspaper said Cameron’s view was: “There is not a long-term, stable, peaceful future for Syria where Syrian people can return home with President Assad as its leader.”
Asked whether Assad could remain during a transition period, the source said Cameron would not demand he immediately steps down.
German Chancellor Angela Merkel also said last week it was necessary to speak to “many actors, among them Assad.”
German government officials, however, denied Merkel was backing the positions of Spain or Austria, who see Assad as possibly playing a role in an interim solution for Syria that would involve joining with international military forces to defeat Islamic State.
Critics have been urging Western power-brokers to be more decisive in the Middle East and Syria, where the United Nations has said 250,000 people have died after four years of conflict, and say lack of a clear policy has given Islamic State opportunities to expand.
