In a setback to South Korean giant Samsung Electronics, US President Barack Obama's trade representative last week vetoed a ban on imports of some Apple iPads and older iPhones.
US Trade Representative (USTR) Michael Froman overruled a June decision by the US International Trade Commission (ITC), which had banned imports of the iPhone 4 and some variations of the iPad 2.
The commission had ruled that the Chinese-made Apple devices violated a patent held by Samsung and couldn't be imported. The ban never went into effect though, because the Obama administration had 60 days to decide if it would uphold the commission.
Samsung and Apple are in a global legal battle over smartphones. Apple argues Samsung's Android phones copy vital iPhone features. Samsung is fighting back with its own complaints.
Froman, in a letter to ITC, wrote he has concerns about patent holders getting too much leverage over competitors that use their technology under licenses.
The iPhone 4 was launched in 2010 and is the oldest iPhone still sold by Apple. The ITC ruling applied only to the AT&T version of the phone. Apple is likely to retire the model.
Apple launched the iPad 2 in 2011. The ruling applies only to the version equipped with a cellular modem for AT&T's network.
The ruling also applies to older iPhones, though these are no longer sold by Apple.
In an email, Apple spokeswoman Kristin Huguet said the company applauded the administration "for standing up for innovation."
Samsung in a statement late Saturday night said it was disappointed in Froman's ruling, saying the ITC "correctly recognised that Samsung has been negotiating in good faith, and that Apple remains unwilling to take a license."
Meanwhile, the South Korean government on Monday voiced "concern" at the overruling.
This is the first time the USTR has overruled the commission since 1987, and South Korea's trade ministry made its feelings clear.
"Our ministry expresses concern about negative impacts the decision by the USTR will have on protecting patents held by Samsung," it said in a statement.
The ministry also said it would "closely watch" a ITC ruling expected on August 9 on whether some Samsung devices violated Apple's patent.
"We hope that the ruling by the USITC...and further decisions by the US administration will be made on fair and reasonable grounds," the statement said.
Samsung is the world's largest maker of smartphones. Analysts estimate it outsold Apple nearly 2 to 1 in the first three months of the year. However, Apple's smartphone business is more profitable.