"Obama must know that the change he talks about is a fundamental change and not changing of colors or tactics," Parliament Speaker Ali Larijani said in comments on state radio.
Larijani, echoing Iran's official line, called on Obama to carry out his campaign slogans of U.S. foreign policy change, including change to U.S. dealings with Iran.
"Repeating objections to Iran's nuclear program will be taking a step in the wrong direction."
Obama, at his first news conference since Tuesday's election, said on Friday an international effort must be made to keep Iran from developing a nuclear weapon, adding that the country's development of a nuclear weapon was "unacceptable."
The West believes Iran's nuclear enrichment program is aimed at building atomic weapons, an allegation Tehran denies.
Larijani said Iran would not yield to international pressure to abandon its right to nuclear technology.
"You (Obama) should know that you (the United States) cannot prevent Iran (from obtaining nuclear technology)," the official IRNA news agency quoted Larijani as saying.
Iranian officials have repeatedly rejected world powers' demand that it halt uranium enrichment, a process which can have both civilian and military purposes, in exchange for trade and other economic benefits.
Iran's defiance has drawn three rounds of U.N. sanctions since 2006 as well as bilateral U.S. punitive measures.
The United States cut diplomatic ties with Iran shortly after its 1979 Islamic Revolution and is now spearheading a drive to isolate the country over its nuclear activities.
A senior Iranian official called on Obama on Thursday to show goodwill and remove "cruel" sanctions imposed on the Islamic Republic.
Obama has said he would harden sanctions on Iran but has also held out the possibility of direct talks with U.S. adversaries to resolve problems, including the dispute over Tehran's nuclear ambitions.
(Writing by Parisa Hafezi; Editing by Louise Ireland)
