Sanctions were first eased late last year after a devastating earthquake in the Iranian city of Bam left 26,000 people dead and many homeless. The move was intended to allow for humanitarian relief to enter Iran.
The suspension of sanctions, set to expire last month, was renewed for another 90 days starting 25 March.
It's unclear why the United States is making the move now. The Iranian government has not yet reacted.
"Given the U.S.-Iran relations, even humanitarian gestures are political -- so I think this is a significant gesture," Amirahmadi said. "It is at least partly political, if not totally. U.S.-Iran relations need small openings like this to move forward."
Amirahmadi added that although Bam has not been rebuilt, the immediate emergency situation is over. He believes the U.S. decision is more of a goodwill gesture that will be well received in Iran.
David Phillips is a senior fellow and deputy director of the Center for Preventive Action at the Council on Foreign Relations. Phillips said the original move to ease sanctions was more than a humanitarian move.
"That decision was extended after the Bam earthquake and it was done as a humanitarian gesture -- I remember, however, that when the easing of the sanctions was announced it was done in the context of a broader discussion about political reforms in Iran," Phillips said. "In that sense it sent some signals to the Iranians about the intent and purposes behind the easing of humanitarian sanctions."
Phillips, who visited Iran in December, said working together on humanitarian issues is one way of breaking down barriers.
"The Iranians I spoke to all expressed a very keen desire to have contacts with Americans and to establish contacts between Iranian and U.S. officials on subjects where the two countries have overlapping concerns," Phillips said.
Most analysts see a long road ahead for any real improvement in bilateral relations.
The two countries broke diplomatic ties after the 1979 revolution and the U.S. hostage crisis. Tensions between the two increased in 2002 after U.S. President George W. Bush labeled Iran part of an "axis of evil" with Iraq and North Korea.
U.S. officials continue to be suspicious of Iran's nuclear program. Iranian officials deny the allegations.
Despite the accusations and suspicions on both sides, observers say that in recent months there have been a number of positive developments. Last week in Baghdad, a U.S. diplomat attended a meeting between an Iranian delegation and British officials. In January, Iranian Foreign Minister Kamal Kharrazi and U.S. Senator Joseph Biden (Democrat, Delaware) spoke for about 90 minutes on the sidelines of the World Economic Forum in Davos.
Houshang Amirahmadi said extending the easing of U.S. sanctions is just one item on a list of recent goodwill gestures. He said he believes the most significant development was Iran's signing recently of the additional protocol to the Non-Proliferation Treaty.
"This has been the most significant development, I think, in the U.S.-Iran relations in the last 20 years," Amirahmadi said. "In fact, Iran has been trying to respond to the most significant American concern towards Iran's international behavior, and that's the nuclear issue."
But he agreed the problems will not be resolved overnight.
"I think the process will be very slow and we will still have problems ahead," Amirahmadi said. "I'm sure there will be times when this relation will go back down, but I think ups and downs in the relationship have been a constant -- but to me, it seems from the trend of the last several months we are moving in the direction of more ups than downs."