In a BBC interview broadcast Tuesday, he also restated plans to pursue direct diplomacy with Tehran to encourage it set aside any ambitions for nuclear weapons it might harbor.
Iran has insisted its nuclear program is aimed at generating electricity. But the U.S. and other Western governments accuse Tehran of seeking atomic weapons.
"What I do believe is that Iran has legitimate energy concerns, legitimate aspirations," Obama said, adding that the international community also "has a very real interest" in preventing a nuclear arms race.
The president has indicated a willingness to seek deeper international sanctions against Tehran if it does not respond positively to U.S. attempts to open negotiations on its nuclear program. Obama has said Tehran has until the end of the year to show it wants to engage with Washington.
"Although I don't want to put artificial time tables on that process, we do want to make sure that, by the end of this year, we've actually seen a serious process move forward. And I think that we can measure whether or not the Iranians are serious," Obama said.
Obama's interview offered a preview of a speech he is to deliver in Egypt this week, saying he hoped the address would warm relations between Americans and Muslims abroad.
"What we want to do is open a dialogue," Obama told the BBC. "You know, there are misapprehensions about the West, on the part of the Muslim world. And, obviously, there are some big misapprehensions about the Muslim world when it comes to those of us in the West."
Obama leaves in the evening on a trip to Egypt and Saudi Arabia aimed at reaching out to the world's 1.5 billion Muslims. He is due to make his speech in Cairo on Thursday.
Obama sounded an optimistic note about making progress toward resolving the Israeli-Palestinian conflict, although he offered no new ideas for how he might try to secure a freeze on new building of Israeli settlements. The United States has called for a freeze, but Israeli leaders have rejected that.
Asked what he would say during his visit about human rights abuses, including the detention of political prisoners in Egypt, Obama indicated no stern lecture would be forthcoming.
He said he hoped to deliver the message that democratic values are principles that "they can embrace and affirm."
Obama added that there is a danger "when the United States, or any country, thinks that we can simply impose these values on another country with a different history and a different culture."