Kuwait: The head of the Syrian National Coalition opposition group says a thaw in relations between Washington and Tehran could strengthen President Bashar al-Assad's hand in Syria's civil war.
Ahmed Jarba said a disbursement of Iranian funds frozen in overseas bank accounts as part of a deal under which Iran is to curb its nuclear activity in exchange for sanctions relief could leave it more cash to spare to support Dr Assad.
"I am worried about this closeness (in relations) from the financial side," Jarba said in an interview with Reuters, referring to relations between the United States and Iran.
"There are frozen Iranian funds in foreign banks. If these funds were released to Iran, part of it could go to the Syrian regime and this complicates matters even more," he said during a visit to Kuwait, which hosts a Gulf Arab summit on Tuesday.
"We have conveyed this worry to the Arab and international parties and they were understanding," he said.
Iran is the main backer, along with Russia, of Dr Assad's government in a conflict that has lasted more than two years, killed more than 100,000 people and uprooted millions.
Western diplomats say Iran provides Syria with billions of dollars of aid and an undisclosed number of military advisers.
Dr Assad has consolidated his power around Damascus and central Syria after months of steady military gains. He faces little internal pressure to make concessions to the mainly Sunni rebels.
Infighting among Syria's rebel groups has undermined their fight against Dr Assad and made Western governments hesitant to back them.
Mr Jarba said the coalition would try to unify factions inside Syria ahead of the "Geneva 2" peace talks scheduled for January next year.
"There are efforts to unify the opposition on the ground ... the armed opposition. We will meet in Turkey this month," he said, adding factions would include the new Islamic Front, a union of six rebel groups, but not al Qaeda-linked groups.
The Syrian National Coalition has little physical presence in Syria and little influence over militant Islamist brigades that play a major role in the fight against Dr Assad's forces.
In a sign of the friction among rebel groups, fighters from the Islamic Front took control of the Western-backed Free Syrian Army bases on the Turkish border, rebels and activists said on Saturday.
The rise of hardline Islamist groups, including some linked to al Qaeda, has unsettled powers including the United States, who fear that if the militants came to power, they would eventually turn their weapons on Western targets.
While the Islamic Front does not include either of Syria's two al Qaeda-affiliated units - the Nusra Front and the Islamic State of Iraq and the Levant (ISIL) - it does include radical Islamists who have coordinated with them.