US President George Bush on Wednesday said Syria should withdraw its military and its secret services from Lebanon.
Iranian Foreign Minister Kamal Kharrazi said Washington was trying to protect its chief ally in the region, Israel.
"The Lebanese must beware of falling into the trap of foreigners who, using beautiful words, pursue their own political objectives," he said.
"To secure the interests of Israel in the region, the Americans are putting pressure on Syria to withdraw its forces," Kharrazi told the official IRNA news agency in Tehran on Wednesday.
Thousands of Lebanese have protested in the streets of Beirut after last week's assassination of former Lebanese Prime Minister Rafiq al-Hariri, calling for the withdrawal of Syrian troops.
"The Lebanese must beware of falling into the trap of foreigners who, using beautiful words, pursue their own political objectives"
Iranian foreign minister
But Kharrazi said: "It is the Lebanese officials who have to decide about the withdrawal of Syrian forces and America's insistence and that of some European states is interference in Lebanon's internal affairs."
Iran and Syria, both locked in rows with the United States, said during the visit of Syrian Prime Minister Naji al-Otari to Tehran last week that they would form a common front to face challenges and threats.
Bush said Washington would wait to see how Syria responded before possibly seeking United Nations sanctions.
"We will see how they (Syrians) respond before there are any further discussions about going back to the United Nations," he told a news conference after talks with German Chancellor Gerhard Schroeder on Wednesday.