France is to suspend diplomatic contacts with Syria, French President Nicolas Sarkozy has announced.
President Sarkozy wants Syria to use its influence in Lebanon
Links will be restored only when France has proof that Syria is not blocking progress towards installing a consensus president in Lebanon, Mr Sarkozy said.
Lebanon has been without a president since November, as rival pro- and anti- Syrian factions argue over who should fill the post.
"I ask Syria to... work to create agreement," said Mr Sarkozy.
France "will not make any more contacts with Syria... as long as there is no proof of Syria's willingness to let Lebanon choose a consensus president," he told reporters, during a visit to Egypt.
BBC correspondent Heba Saleh in Cairo says attempts to install a new Lebanese president have stalled because of the standoff between the pro-Western government and the opposition backed by Syria and Iran.
France has attempted to mediate between the two sides and agreement has been reached on a compromise candidate - army commander Gen Michel Suleiman.
But the rival factions cannot agree on how to share power once Gen Suleiman assumes his position.
France now hopes that putting pressure on Syria will move the process forward.
Syrian troops occupied Lebanon for 30 years until they withdrew in 2005, and Syria retains considerable influence on political life in its neighbour.