Syria's foreign minister said on Friday it was premature to talk of direct peace negotiations with Israel, a day after Israeli Prime Minister Ehud Olmert called for quickly starting face-to-face negotiations.

A third round of talks between the long-time foes started in Istanbul on Tuesday and ended on Thursday with an agreement to hold a fourth round of indirect negotiations in Turkey in late July, a Turkish government source told Reuters on Thursday.

"It's premature to answer this question," said Walid al-Moualem when asked when direct talks could be held.

"The moment when we feel that we've got the agreed common ground between us and the Israelis, which covers all elements of a peace agreement, we will agree on the location of these direct talks," he said in a question and answer session at the French Institute for International Relations (IFRI).

Israeli Prime Minister Ehud Olmert on Friday called for quickly starting face-to-face negotiations with Syria after the third round of indirect peace talks mediated by Turkey ended with an agreement to meet again.

Syria, demanding that Israel return all of the Golan Heights occupied in 1967, insists peace talks can only succeed with the full involvement of Washington -- unlikely to materialize under President George W. Bush, who views Damascus as an "evil" ally of Iran and of groups hostile to U.S.-Israeli interests.

"The direct talks need an active American participation and sponsoring. To give guarantees we need an active European role maybe represented by France. We need also a role for Russia, a role for the United Nations for these talks," he said.