Addressing a packed press conference in a New York hotel, Ahmadinejad also said Iran was prepared to set a date for resumption of talks with six world powers to discuss Tehran's nuclear program, saying October would be the likely time for the two sides to meet.
Ahmadinejad also defended his remarks at the U.N. a day earlier in which he claimed most people in the world believe the United States was behind the Sept. 11, 2001 terror attacks and again challenged the United Nations to set up a commission to probe the attacks.
"I did not pass judgment, but don't you feel that the time has come to have a fact finding committee?" Ahmadinejad asked.
Ahmadinejad said Iran had no interest in enriching uranium from around 3.5 percent to 20 percent purity but was forced to do so after the world powers refused to provide nuclear fuel that is needed for a Tehran reactor that produces medical isotopes for patients. He did not indicate that Iran would stop enriching at low levels.
That level is far below the more than 90 percent purity needed to build a nuclear weapon, but U.S. officials have expressed concern Iran may be moving closer to an ability to reach weapons-grade level.
Tehran began higher enrichment in February after talks stalled over a U.N.-brokered proposal that the United States hoped would - at least temporarily - leave Iran unable to produce a warhead. The U.S. and its allies accuse Iran of seeking to build a nuclear weapon, a claim Iran denies.
"We were not interested to carry out 20 percent enrichment. They (the U.S. and its allies) politicized the issue. We were forced to do it to support the (medical) patients," Ahmadinejad said in response to a question from The Associated Press. "We will consider halting uranium enrichment whenever nuclear fuel is provided to us."
Ahmadinejad said pressure was counterproductive, but respectful talks will bear fruit.
"The era of following a policy of carrot and stick is over. Even such words are insulting to nations. It's only good for cowboys and those of retarded people. Definitely it has no effect," he said. "They issued resolutions as talks were underway. Still, we are ready for talks."
The Iranian leader said an Iranian representative will probably meet with members of the five permanent members of the Security Council - the U.S., Britain, France, Russia and China as well as Germany in October.
He suggested that a specific date could be set should European Union foreign policy chief Catherine Ashton contact Iran.
"Probably in October; we are ready for talks. The doors are open for talks within the framework of justice and respect," he said. However, he warned that Iran won't give in to pressure. "They are definitely mistaken if they think they can trample the rights of the Iranian nation through coercion in the talks."
In his one and a half hour session with reporters, Ahmadinejad also lashed out at the U.S. wars in Iraq and Afghanistan as an overreaction to the September 11 attacks. The Americans should "not occupy the entire Middle East...bomb wedding parties...annihilate an entire village just because one terrorist is hiding there."
Ahmadinejad also gave no ground on his Sept. 11 remarks in a feisty interview on Fox News in which he was asked he you could insult millions of Americans by saying "such an insane and nutty thing."
"Would you address your own president the same way? Would they ever allow you to?," replied Ahmadinejad, adding that he felt insulted by the interviewer.
Ahmadinejad said a commission should investigate the Sept. 11 attacks rather than have the entire world just accept what the U.S. government tells them.
"The fact-finding mission can shed light on who the perpetrators were, who is Al Qaeda ... where does it exist? Who was it backed by and supported? All these should come to light," he said.
Ahmadinejad's remarks during a speech to the U.N. General Assembly Thursday afternoon prompted a walkout by the U.S. diplomats. Delegations from all 27 European Union nations followed the Americans out along with representatives from Australia, New Zealand, Canada and Costa Rica, an EU diplomat said.
President Barack Obama responded to Ahmadinejad in a BBC Persian service interview Friday saying: "Well, it was offensive. It was hateful."
"And particularly for him to make the statement here in Manhattan, just a little north of Ground Zero, where families lost their loved ones, people of all faiths, all ethnicities who see this as the seminal tragedy of this generation, for him to make a statement like that was inexcusable," Obama said.
Ahmadinejad routinely makes incendiary remarks, which the West claims are a diversion from heavy international pressure on Tehran to end uranium enrichment and prove that it is not trying to build a nuclear weapon. Iran insists it is enriching uranium only to fuel nuclear reactors to generate electricity.
Iran is under four sets of U.N. Security Council sanctions as punishment for its failure to make its nuclear ambitions transparent.
Later Friday, Ahmadinejad met with Sarah Shourd, one of three Americans who were taken prisoner in Iran during a hiking trip along the border with Iraq. She was released from solitary confinement on Sept. 15 and has said she wants to meet Ahmadinejad while he is in New York.
The Iranian leader did not answer a question about whether Iran would also release Shourd's boyfriend Shane Bauer and their friend Josh Fattal. All three were captured in 2009.