"We are awaiting concrete changes from new US statesmen," government spokesman Gholam Hossein Elham was quoted as saying by the ISNA news agency.
"On several occasions our president has defined Iran's views and the need for a change in US policies," he said.
His comments followed an interview Obama gave to pan-Arab satellite television channel Al-Arabiya in which he extended a diplomatic hand to the Muslim world and said the United States would in the next few months lay out a general framework of policy towards Tehran.
"As I said in my inauguration speech, if countries like Iran are willing to unclench their fist, they will find an extended hand from us," Obama said.
"It is very important for us to make sure that we are using all the tools of US power, including diplomacy, in our relationship with Iran."
Echoing President Mahmoud Ahmadinejad's position, Elham said the United States "should accept it is a government within its own limits not an empire."
Washington accuses Tehran of seeking nuclear weapons under the guise of a civilian atomic programme — charges that Tehran vehemently denies.
On Monday, Washington's new UN ambassador, Susan Rice, pledged "direct" nuclear diplomacy with the Islamic republic as long as Tehran halts uranium enrichment.
Uranium enrichment lies at the centre of fears about Iran's nuclear programme as the process can be used to make nuclear fuel as well as the fissile core of an atom bomb in highly purified forms.
Despite five UN Security Council resolutions, Tehran is pressing on with enrichment, insisting its nuclear programme is peaceful and solely geared toward electricity generation.
The Security Council has imposed three sets of sanctions on Iran for defying international calls to stop enrichment but Tehran has so far ruled out suspending the process as a pre-condition to talks.
Washington also accuses the Islamic republic of meddling in Iraq as well as supporting terrorism by arming and financing militant groups in the Middle East.
Iran has also said it wants a change of US policy towards Israel and Palestinians. It does not recognise the Jewish state and is a staunch supporter of Hamas.
Earlier this month Ahmadinejad accused Obama's yet-to-take-office government of hostility towards the people of Gaza when it was under Israeli attack, and urged the new administration to "condemn the Zionist regime and not support it."
Washington severed ties with Iran in 1980 in the wake of the Islamic revolution after Islamist students stormed the US embassy in Tehran and held 52 diplomats hostage for 444 days.
The US administration of former president George W. Bush refused to engage in direct negotiations with Iran unless it first stopped enriching uranium and spearheaded pressure for economic sanctions against the Islamic republic.
