"They have this excuse that Iran is dodging negotiations while it is not the case," Ahmadinejad was quoted as saying by state-run TV. "Why should we run away from the negotiations?"
Ahmadinejad's statements could be seen as a reaction to increased pressure placed on Iran by the United States and the European Union during recent months, the International Business Times reported.
In his speech broadcast on state television, Ahmadinejad accused the West of trying to hamper negotiations to put increased pressure on Iran, the BBC said.
"It is the West that needs Iran and the Iranian nation will not lose from the sanctions," he said. "It is you who come up with excuses each time and issue resolutions on the verge of talks so that negotiations collapse."
Western nations say they fear Iran's nuclear program is an effort to develop nuclear weapons technology while Iran maintains it is for peaceful purposes only.
The European Union formally adopted an oil embargo against Iran and a freeze of the assets of the country's central bank Monday.
Under the sanctions, the 27 members agreed not to sign new oil contracts with Iran and to sever existing contracts by July 1. Ministers also agreed to financial sanctions against the Iranian central bank and to restrict exports of gold and "dual-use goods and technology."