(Adds Rice comments on Iraq, Iraqi envoy, background)
By Louis Charbonneau
UNITED NATIONS, Feb 26 (Reuters) - Iran went on the offensive against the Obama administration on Thursday, accusing Washington's new U.N. ambassador of making the "same tired" accusations against Iran as the Bush administration.
In a speech to the Security Council during a session on Iraq, U.S. envoy Susan Rice reiterated charges of Iranian support for terrorism and attempts to develop nuclear weapons, saying the United States sought an end to both policies.
"It is unfortunate that, yet again, we are hearing the same tired, unwarranted and groundless allegations that used to be unjustifiably and futilely repeated by the previous administration," Iran's envoy Mohammad Khazaee said in a letter to the council's president, Japanese Ambassador Yukio Takasu.
"Instead of raising allegations against others, the United States had better take concrete and meaningful steps in correcting its past wrong policies and practices vis-a-vis other nations, including the Islamic Republic of Iran."
Khazaee's remarks were among the most critical of the new U.S. administration by a senior Iranian official. Iran is not in the Security Council and no Iranian official attended the meeting at which Rice spoke.
The comments on Iran by Rice, who sits in the cabinet of President Barack Obama, were made almost in passing during a periodic Security Council review of U.N. activities in Iraq.
U.S. policy "will seek an end to Iran's ambition to acquire an illicit nuclear capacity and its support for terrorism," Rice told the 15 council members.
Obama, Rice and Secretary of State Hillary Clinton have said repeatedly that Washington would use all tools, including direct talks, to deal with Iran's nuclear program, which Tehran says is for peaceful purposes.
Iran has reacted cautiously, saying it was open to fair talks while demanding fundamental changes in U.S. policy.
"NEW COURSE" ON IRAQ
Tehran often criticized the administration of former U.S. President George W. Bush, which labeled Iran a member of an "axis of evil" with North Korea and pre-war Iraq, but has toned down its rhetoric since Obama took office five weeks ago.
Although a senior U.S. official sat at a negotiating table with an Iranian official in Geneva last year, the Bush administration balked at the idea of direct nuclear talks, preferring instead to try to isolate Iran.
Washington severed diplomatic relations with Iran in 1980 after militants stormed the U.S. embassy in Tehran and took a group of diplomats and officials hostage.
Rice also told the council the United States will move "responsibly and safely" to reduce its military presence in Iraq under a "new course" the Obama administration will adopt.
She gave no details of steps Obama is expected to announce on Friday to begin pulling U.S. combat troops out of Iraq. Bush ordered the U.S.-led invasion in 2003.
Iraq's Ambassador Hamid al-Bayati was asked by reporters about his government's plan to expel some 3,500 Iranian exiles who have been based at a camp in Iraq for two decades.
"They can't stay in Iraq anymore," he said, adding the exiles can either go back to Iran or find a third country. "The People's Mujahideen is an organization which is not welcome."
Human rights groups say forcing the Iranian exiles to return to Iran, where they could be jailed or executed, or move to a third country is a violation of their human rights. Iraq says the exile group is a terrorist organization. (Additional reporting by Patrick Worsnip; Editing by John O'Callaghan)