The comments by Supreme Leader Ayatollah Ali Khamenei, who has the final say on all policy in Iran, are likely to disappoint the new U.S. administration which has been seeking to engage Iran but has called on Tehran to "unclench its fist".
"Even the new president of America, who has come to power with slogans about changing Bush's policies, is defending state terrorism by talking about unconditional commitment to Israel's security," Khamenei told a conference on the Palestinian issue in Tehran.
Khamenei also said Obama was following the same "wrong path" of his predecessor in the White House.
The United States has long called on Iran to end its opposition to peace-making in the Middle East and stop supporting organisations like Lebanon's Hezbollah and the Palestinian Hamas group that Washington considers terrorist.
