Phone maker Nokia has said it will "defend itself vigorously" after Apple launched the latest salvo in an ongoing legal wrangle between the two firms.
On 15 January, Apple filed a complaint with the US International Trade Commission (ITC) asking it to block Nokia imports to the US.
It is the latest move in a series of legal proceedings that started in October when Nokia sued Apple.
The Finnish firm alleged that Apple's iPhone infringed 10 of its patents.
Apple countered by filing its own lawsuit against Nokia, saying the phone maker had copied certain aspects of the iPhone and infringed 13 of its patents.
In late December, Nokia filed a further claim with the ITC, alleging Apple infringed seven of its patents in "virtually all of its mobile phones, portable music players, and computers".
Apple told the BBC that it would not comment on its latest legal move.
However, Nokia said it would "study the complaint and defend itself vigorously".
"This does not alter the fact that Apple has failed to agree appropriate terms for using Nokia technology and has been seeking a free ride on Nokia's innovation since it shipped the first iPhone in 2007," a spokesperson said.
Apple is also being sued by camera maker Kodak over technology used in the iPhone.