Syrian militant commanders from the Islamic Front which seized control of bases belonging to Western-backed militants last week are due to hold talks with U.S. officials in Turkey in coming days, opposition sources said.

Syrian militant commanders from the Islamic Front which seized control of bases belonging to Western-backed militants last week are due to hold talks with U.S. officials in Turkey in coming days, opposition sources said on Saturday, Reuters reported.

The expected contacts between Washington and the radical militants reflect the extent to which the Islamic Front alliance has eclipsed the more moderate Free Syrian Army brigades - which Western and Arab powers tried in vain to build into a force able to fight the Syrian army.

The talks could also decide the future direction of the Islamic Front, which is engaged in a standoff with al-Qaeda-linked Islamic State in Iraq and the Levant (ISIL).

A militant with the Islamic Front said he expected the talks in Turkey to discuss whether the United States would help arm the front and assign to it responsibility for maintaining order in the rebel-held areas of northern Syria.

Diplomatic sources in Turkey said that U.S. Syria envoy Robert Ford was expected in Istanbul soon but his schedule was not yet confirmed.

The Islamic Front, formed by the unification of six major Islamist groups last month, seized control a week ago of weapons stores nominally under the control of the Free Syrian Army's Supreme Military Command (SMC).

It has since said it was asked to take over the base by the SMC to protect it from attack by ISIL fighters. Whether or not the move was requested, it demonstrated how little power the Western-backed SMC wields in rebel-held Syria.

An SMC militant commander also said he had been told the Islamic Front would hold talks with U.S. officials in Turkey in the coming days.