A judge will decide within the next few days whether to indict or free four Iranian-Americans charged with endangering national security, Iran's judiciary spokesman said Tuesday.

Iran's foreign minister, meanwhile, said the United States would "regret" its decision to detain five Iranian officials in Iraq — a case that has further riled U.S.-Iranian relations, already strained over Iran's nuclear program.

Ali Reza Jamshid, the judicial spokesman, said a judge would complete his preliminary investigation into the charge against the four Iranian-Americans "within the next two or three days."

Jamshidi said all four Iranian-Americans have been charged with acting against national security. Several weeks ago, he said they had also been charged with espionage, but he did not repeat that charge Tuesday.

The four include Haleh Esfandiari, director of the Middle East program at the Woodrow Wilson International Center for Scholars, who was jailed in Iran in early May.

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The others are Kian Tajbakhsh, an urban planning consultant with George Soros' Open Society Institute; Parnaz Azima, a journalist who works for the U.S.-funded Radio Farda; and Ali Shakeri, a founding board member of the University of California, Irvine, Center for Citizen Peacebuilding.

Azima is out of jail on bail but not allowed to leave the country; the other three remain in custody.

President Bush has demanded that Iran "immediately and unconditionally" release the four scholars and activists held there. Secretary of State Condoleezza Rice recently told The Associated Press the four were accused "of things that clearly are untrue."

Family, colleagues and employers have also denied the allegations.

The U.S. military has said the five Iranians detained in Iraq in January are suspected of links to a network supplying arms to insurgents — an accusation that Iran has denied.

Iran claimed the men were diplomats and that the building U.S. troops occupied was a government liaison office. It also says the five were the guests of the Iraqi government and has demanded their release. Iraqi government officials have also called for their release, along with compensation for damages.

"We will make the Americans regret their ugly and illegal act," Foreign Minister Manouchehr Mottaki was quoted by the official IRNA news agency as saying. He did not elaborate.

However, Mottaki added that Iran was still willing to continue direct talks with the United States on Iraq, which began first last month in Baghdad and which broke a 27-year diplomatic freeze between the two foes.

Iran's ambassador to Baghdad, Hasan Kazemi Qomi, who represented Iran at the May talks, said the issue of the "freedom of the diplomats" would be on the agenda of future Iran-U.S. talks.

Jamshidi, the judicial spokesman, denied that Iranian lawyer and 2003 Nobel Peace prize laureate Shirin Ebadi was not permitted access to her client, Esfandiari.

Esfandiari's husband, Shaul Bakhash, said the charges against his wife are "baseless," but said he hoped any decision by Iran's judiciary would provide some clarity in the case. The only information Esfandiari's relatives in the Washington area and Iran have comes from vague statements from Iranian government spokesmen.

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"After 36 days in solitary confinement, it is about time the judiciary reached a decision in this matter," he said from his home in Potomac, Md. "Any decision to go to trial or to continue making false accusations against my wife would obviously be a miscarriage of justice."

International human rights groups, including the New York-based Human Rights Watch, have expressed deep concern for the health of the detained Americans — especially Esfandiari, who is 67 — held in Tehran's notorious Evin prison.

Jamshidi said Esfandiari was "in complete health" and that she will be dealt with in accordance with the law. Esfandiari's husband, however, said neither her family nor her lawyers had been able to confirm she was in good health.

The Iranian Intelligence Ministry has accused Esfandiari and her organization of trying to set up networks of Iranians with the ultimate goal of creating a "soft revolution" in Iran, along the lines of the revolutions that ended communist rule in Eastern Europe.

Esfandiari had been trapped in Iran since visiting her 93-year-old mother in December, when three masked men with knives stole her luggage and passport as she headed to the airport to leave, the Wilson Center said. In the weeks before her arrest, she was called in for questioning daily, it said.

Iran has escalated accusations against the U.S., saying last week it had uncovered spy rings organized by the U.S. and its Western allies.