"Quite frankly, this American administration is not interested in the peace process, so the question [of direct talks] won't arise before the arrival of a new American administration," al-Assad said.
Presidential elections will be held in the US in November and George Bush, the current US president, will leave office in January next year.
After al-Assad spoke, Rob McInturff, a US state department spokesman, said that Washington would "continue to limit our diplomatic engagement unless Syria takes concrete actions to end its destabilising tactics in the region".
Israel and Syria, which have technically remained at war since the creation of the Jewish state in 1948, have held three rounds of indirect talks through Turkey since March.
The last round of direct negotiations under US sponsorship eight years ago collapsed, with Washington unwilling to re-engage Syria because of its close links to Iran and its role in Lebanon.
Al-Assad also asserted that Iran was not intent on developing nuclear weapons and and that the solution to the conflict over the country's nuclear policy should be solved politically rather than militarily.
"What we're interested in is finding a political solution," he said.
Al-Assad made the comments at a joint news conference with Sarkozy and Michel Sleiman, his Lebanese counterpart.
The three men will join 41 other foreign delegates, including Ehud Olmert, the Israeli prime minister, at a summit of the Union for the Mediterranean.
Last week, Olmert, had said face-to-face talks would be held "very soon".
"With the Syrians, we are talking seriously and, in my estimation, very soon the negotiations will have to be direct," he said.
"They will not be able to continue in the manner in which they are currently being held."
However, a meeting between al-Assad and Olmert on the sidelines of the talks has been ruled out.
The Mediterranean union comprises 44 nations - 27 from Europe and 17 from north Africa and the Middle East. The leaders will be discussing issues such as immigration, student exchange programmes and pollution.