"Mr. Obama has only one chance and that is Iran. This is not an emotional comment, it's scientific. Obama cannot do anything in Palestine, they won't let him do anything and he has no chance," Ahmadinejad was quoted as saying in an interview with Iran's state television.
The Iranian president also said that Obama has no chance of success in Iraq and Afghanistan.
"What can he do in Iraq? Nothing. And Afghanistan is too complicated."
Ahmadinejad added that he is drafting a new letter to Obama that will be published in "due time". Ahmadinejad sent an unprecedented letter to Obama shortly after his election in 2008 and congratulated him on his victory.
The Iranian president has in the past five years written several letters to world leaders, including one to former U.S. President George W. Bush and to German Chancellor Angela Merkel.
In his latest letter, addressed to UN Secretary-General Ban Ki-moon, Ahmadinejad has called for an investigation into the September 11, 2001, terrorists attacks.
"At least, you are expected to form an independent fact-finding committee trusted by regional countries on major elements behind September 11 attack, which was carried out as the main pretext to attack the Middle East," Iran's Student News Agency (ISNA) has quoted Ahmadinejad as saying in the letter.
Ahmadinejad last month said that the 9/11 attacks on the United States that left some 3,000 dead were a "big fabrication" that was used to justify the U.S.-led war on terrorism.
-- Golnaz Esfandiari