The US has eased restrictions on the sale of mobile phones and other communications devices, software and services to Iranians.
The move is intended to promote Iranians' political freedom, countering what the US describes as Tehran's efforts to "silence its people".
The shift marks the first time Apple's iPhone can be exported legally to Iran.
The US had toughened sanctions in recent years in an effort to force Iran to curb its nuclear programme.
The US believes Iran is enriching uranium to levels that could be used in a nuclear weapon, but Iran insists its programme has peaceful objectives.
"The people of Iran should be able to communicate and access information without being subject to reprisals by their government," the US treasury department said in a statement.
It said it would allow sales of equipment and software to Iranians but said the government and people on a list of "specially designated nationals" remained barred from export licences.
"We certainly care deeply about the Iranian people and their day-to-day lives," Wendy Sherman, the state department's undersecretary for political affairs, told the BBC Persian service on Wednesday.
"That general license will allow both software and hardware to move forward to Iran and to the Iranian people so that they can have freedom to communicate with each other in ways that they don't always have."
The National Iranian American Council welcomed the move.
"Lifting these sanctions is an extremely positive step," said policy director Jamal Abdi.
"There was no better example of sanctions that undermined human rights and civil society efforts of Iranians, and helped the regime."
In recent years, Iranians in the US have complained Apple retail stores had refused to sell them iPhones or iPads, with employees saying they feared the devices would be illegally shipped to Iran.
The move comes just weeks ahead of elections in Iran.
Social media played a prominent role in the disputed 2009 elections that returned President Mahmoud Ahmadinejad to power. Green Movement opposition protesters used social media extensively to organise street demonstrations.