In an interview with French daily Le Figaro published on Friday, Assad said the dialogue initiated by Obama's administration had not gone "beyond an exchange of views."
"There has not been an executive plan," he said.
Assad is due to meet French President Nicolas Sarkozy on Friday, hot on the heels of Israeli Prime Minister Benjamin Netanyahu who was in Paris earlier this week.
While Netanyahu said he was ready to start peace negotiations with Assad immediately, the Syrian leader accused Israel of not truly wanting to relaunch talks.
"But the weak point is the American sponsor (of peace talks)," Assad told Le Figaro.
"What Obama said about peace was a good thing. We agree with him on the principles, but as I said, what's the action plan? The sponsor has to draw up an action plan," he said.
Assad said that while relations with the United States had improved, issues such as continued US sanctions against Syria were hindering any joint work towards peace in the Middle East.
Asked about Israel's complaint to the United Nations earlier this month about what it said was an Iranian attempt to supply weapons by ship to Lebanese terror group Hezbollah, Assad accused Israel of lying.
"What proof is there that the arms were for Hezbollah or someone else?" he said, adding that a sovereign state had the right to buy arms. He said Israel's seizure of the ship amounted to "an act of piracy in the middle of the Mediterranean."
Peace talks between Israel and Syria faltered in 2000 over the demand by Damascus for a full withdrawal from the Golan Heights, a strategic plateau Israel captured in a 1967 war and later annexed.
Turkey later mediated a limited series of contacts between the two countries, which failed to result in any formal negotiations. Israel accuses Syria of helping to arm Hezbollah and Hamas, its militant enemies in Lebanon and the Gaza Strip.
Assad also said the new unity government formed in Lebanon created stability and made it easier for Syria, which ended its 29-year military presence in Lebanon four years ago, to have normal relations with its neighbor.
"The formation of a unity government automatically means an improvement in Syrian-Lebanese relations, with a view to their normalization," he said.
Lebanon's Prime Minister Saad al-Hariri formed a new unity government on Monday that includes two ministers from Syrian- and Iranian-backed Hezbollah.