"The Iranian nation will not give up until the corrupt leadership in the world has been obliterated," Ahmadinejad said in the Shiite holy city of Mashhad, northeast Iran, quoted by the Fars news agency.

"Our foes should know that threats, sanctions, and political and economic pressures can not force our nation to back down," he added.

Ahmadinejad outlined two goals for the Islamic republic and its people.

"We have two missions, to build Islamic Iran and to exert an effort to change the leadership in the world. We have to carry out both (missions) as well as we can," he said.

The hardline president also renewed his defiance of United Nations demands for Iran to halt sensitive nuclear work.

"The resolutions which are adopted against Iran are ... scraps of papers. The Iranians are a peace-loving people of dialogue in fair circumstances, but they will not discuss their rights," he said.

Ahmadinejad on Wednesday vowed Iran would not halt its nuclear drive in the face of pressure from the West.

The United States this week warned Iran it risked further isolation and new international sanctions after refusing to comply with UN Security Council resolutions over its disputed nuclear programme.

On Tuesday, Ahmadinejad announced Iran has started the installation of 6,000 new centrifuges to enrich uranium at its main nuclear plant in Natanz, prompting expressions of anger and concern from Western countries.

The West fears Iran could use enriched uranium to make a nuclear weapon, and Tehran's refusal to suspend the process has been punished with three sets of Security Council sanctions and US pressure on its banking system.

Iran vehemently denies the claims and maintains that it seeks nuclear energy to address an ever growing population's need for electricity.

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