Iran (search)'s supreme leader on Wednesday said the United States was fomenting tension in Iran and vowed not to give in to American arrogance, state-run television said.

Reacting to accusations from Washington that Iran was harboring Al Qaeda (search) militants, Ayatollah Ali Khamenei (search) said increasing pressure from the United States was designed to force Iran to renounce its Islamic values.

"Where is the final limit to America's pressure? ... Let me tell you where that final limit is: It is when you declare on behalf of the Iranian nation -- and neither you nor I have the right to do this -- that we do not want Islam, we do not want an Islamic Republic, let whoever you think is best come and rule this country," television quoted Khamenei as telling lawmakers.

Khamenei said the latest American accusations were the "final limit" and Iran would not accept them.

"This is the final limit; the start of the land's servility. Can we do this? Can you and I hand the country over to the enemy? This is not why the nation put us in power," Khamenei said.

He accused the United States of trying to whip up unrest among Iranian officials.

"The enemy knows that its arms and weapons are ineffective in the face of the Iranian nation's will and resistance. Thus, it is seeking to stir up social tension and psychological pressures to frighten [Iranian] officials," he was quoted as saying. "This is the result of stupid arrogance of American leaders."

Meanwhile, Iranian Foreign Minister Kamal Kharrazi insisted that it was Iran's policy to crack down on the Al Qaeda network.

"Responsible bodies routinely arrest them. They are returned to their countries and those who have acted against Iran's national security are tried in Iran. Some of them are in our custody and are currently being interrogated," Kharrazi told a news conference.

Iran has said it returned about 150 Al Qaeda militants to their countries, including Saudi Arabia, since Sept. 11, 2001 and denied that it is harboring any members.

During the news conference, Kharrazi did not mention the United States by name.

Kharrazi also rejected U.S. charges that Iran was pursuing a nuclear weapons capability but said Tehran's signing of additional nonproliferation protocols depended on the country being given access to advanced nuclear technology.

"As a signatory to the Nonproliferation Treaty, we believe in transparency. Signing additional protocols should come with lifting all the restrictions imposed on Iran's access to nuclear technology," Kharrazi said.

The United States suspects Iran is trying to make a nuclear bomb and has given credence to a report by the opposition National Council of Resistance of Iran that the Tehran government has built a uranium enrichment plant for bomb materials.

Iran has said it is building such a plant at Natanz, in central Iran, which was visited by the head of the U.N. International Atomic Energy Agency, Mohamed ElBaradei, in February.

Iran said the plant, however, will not be capable of making weapons grade material. ElBaradei is due to issue a report next month.