"I have full faith in President Obama's moral and operational stance," Peres said in an interview with Israeli army radio.
"I recommend patience, I am confident that the United States will respond in the right way to Syria."
Obama said Saturday he will ask the US Congress to authorise military action against Syria over an alleged chemical attack, lifting the threat of immediate strikes on President Bashar Assad's regime.
Peres said the situation in Syria was now more complicated than ever, requiring careful deliberation over foreign intervention.
"There is no one Syria anymore. Syria as it was is no longer. Assad cannot unite Syria, there are three or four countries in one," he said, in apparent reference to various rebel groups fighting to topple the regime.
Peres also ruled out Israeli involvement in any intervention.
"It is not for Israel to decide on Syria, we are in a unique position, for varying reasons there is consensus against Israeli involvement. We did not create the Syrian situation," he said.
Obama, whose surprise decision on Saturday to ask for the OK of lawmakers pushes back any military intervention in Syria until next week at the earliest, has set off on an intense lobbying campaign to get approval.
Washington said on Sunday that it had proof the Damascus regime used sarin gas in a deadly attack on 21 August that precipitated the threat of US-led military retaliation against Syria.
But Assad's regime categorically denies being behind the suspected attack, and its close ally Moscow has said it is totally unconvinced by evidence presented by the United States and its allies.