The quasi-judicial International Trade Commission said it issued a "limited exclusion order" for certain devices made by Apple, in a victory for the South Korean firm after a huge loss in a court fight with its US rival last year.
The loss dealt to Apple by the ITC could make the Cupertino, California-based company more amenable to negotiating settlements on some of the many legal fronts where it is waging patent war with Samsung.
"Up to now, Apple has been winning the big judgments, which means there was no reason to come to the table," said independent Silicon Valley analyst Rob Enderle.
"It looked like Apple held all the cards," he said. "But if this holds up and both companies have something to lose, you can get negotiation."
Tuesday's victory could be largely symbolic because the ban covers devices that are no longer actively sold in the US market -- the AT&T iPhone 4 and iPhone 3 and 3GS, as well as the iPad 3G and iPad 2 3G, also sold by AT&T.
But it is likely that Samsung will explore the feasibility of launching similar legal attacks at newer products from the company, according to Enderle.
"Typically, once you win something like this you try to apply it to the new products," the analyst said. "This may put enough risk on Apple to get them more open to talking with Samsung."
The ITC ruling is a final order but may be appealed in the US Court of Appeals or reversed by presidential order.
"We believe the ITC's final determination has confirmed Apple's history of free-riding on Samsung's technological innovations," a Samsung statement said.
"Our decades of research and development in mobile technologies will continue, and we will continue to offer innovative products to consumers in the United States."
Apple did not immediately respond to an AFP request for comment.
The case was filed in August 2011 amid a flurry of litigation between the two rivals over patents in the hot market for tablets and smartphones.
In a separate patent fight in US federal court, Samsung was ordered last August to pay more than $1 billion for patent infringement, which also opens the door to a ban on some Samsung devices.
A judge later slashed the award to $598.9 million.
Apple has been seeking to ban some of the newer 4G phones from Samsung's Galaxy line, as well as the Droid Charge sold through Verizon in that case, which is being appealed.
The news came on the same day the White House moved to crack down on abuses of the patent system, responding to mounting concern among technology companies over a flood of litigation that some say stifles innovation.
The White House said new action is needed in the face of a flood of recent patent litigation, particularly in the smartphone sector, and because "several major companies spend more on patent litigation and defensive acquisition than on research and development."
The latest moves target so-called "patent trolls" which, according to the White House, "hijack" ideas and take other companies to court with an eye to collecting license or royalty fees.
Meanwhile, Apple has asked a federal judge in Silicon Valley to add Samsung's new flagship Galaxy smartphone to the list of devices targeted in a patent lawsuit involving Siri personal assistant software.
The motion to amend the lawsuit to include the Galaxy S4 will be on the agenda of a June 25 hearing before US District Court Judge Paul Grewal in the California city of San Jose.
The trial is not expected to begin until early next year.
After years of following and refining the iPhone's pioneering innovations -- a strategy that resulted in bitter patent battles with Apple -- Samsung has dethroned its rival to become the world's top smartphone maker.