Syria and Israel have postponed a crucial round of indirect peace talks due to the resignation of the chief Israeli negotiator, said Syrian President Bashar al-Assad yesterday.

But Turkey, which is acting as mediator, said they should resume later this month.

The talks were meant to address specific proposals on how to reach a breakthrough between the long-time foes.

They have already held four rounds of indirect talks which centre on the fate of the Golan Heights, a strategic plateau which Israel captured from Syria in the 1967 Middle East war. Damascus demands the return of all the Golan Heights.

Israel, in turn, wants Syria to scale back ties with its main foes – Iran, the Palestinian Hamas and Lebanese Hezbollah militants groups. Syria has so far refused to do so.

"There was supposed to be a fifth round, meant to be crucial, I think yesterday," Assad said.

"The resignation of the chief Israeli negotiator led to the postponement of this round, which would have defined the course of these negotiations."

Assad said Israel and Syria had separately put forward ideas for a declaration of principles under which they would move to direct talks.

But progress was hampered by internal politics in Israel where Prime Minister Ehud Olmert is stepping down because of corruption charges, which he denies.

An Israeli official said: "We are still interested in the continuation of the talks with a genuine intention to reach an agreement."

Israeli negotiator Yoram Turbowicz announced his resignation as Olmert's chief of staff in July, shortly after the prime minister said he would leave office.

Turbowicz agreed to continue to represent Israel at the Syria talks in a voluntary capacity but Israel's attorney-general has yet to authorise his participation.

Assad did not say when the next round of the Turkish-mediated talks is expected.

"We are now waiting for the Israeli elections to define the future of this stage. We want support of all countries," Assad said at the start of a summit in Damascus to discuss efforts for a peace agreement between Syria and Israel.

The summit, which will look at ways to support stability in neighbouring Lebanon, was attended by French President Nicolas Sarkozy and Qatar's Emir Sheikh Hamad bin Khalifa al-Thani as well as Assad and Erdogan.

Assad said the Syrian proposals for the peace talks focused on defining the extent of Syrian territory under Israeli occupation as a basis for negotiating an Israeli withdrawal.