Samsung Electronics said Tuesday it would take counter-action against Apple after the US firm filed suit alleging that the South Korean giant copied its smartphones and tablet computers.
Apple's lawsuit claims Samsung's mobile phones and Galaxy Tab imitated the iPhone and the iPad.
"Samsung will respond actively to this legal action taken against us through appropriate legal measures to protect our intellectual property," the South Korean firm said in a statement.
Samsung has been successfully developing its own core technologies and building up its intellectual property portfolio, it said.
Yonhap news agency quoted Samsung officials as saying they suspect Apple had violated Samsung's wireless technology patents.
"Apple is one of our key buyers of semiconductors and display panels. However, we have no choice but respond strongly this time," an unidentified official was quoted as saying.
Apple was Samsung's second-largest client in 2010 after Japan's Sony Corp, accounting for four percent of the South Korean firm's 155 trillion won ($142 billion) annual revenues.
Apple accused Samsung of copying the look, product design, packaging and user interface of its products, in a lawsuit filed Friday with a US District Court in San Francisco and quoted by the Wall Street Journal.
It claimed Samsung has violated various Apple patents and trademarks.
"Rather than innovate and develop its own technology and a unique Samsung style for its smartphone products and computer tablets, Samsung chose to copy Apple's technology, user interface and innovative style in these infringing products," the Journal quoted Apple's complaint as saying.
Samsung's Galaxy Tab has been the best-selling rival to the iPad, which has dominated the growing market for the touchscreen devices.
The legal action came as Samsung is scheduled to release the Galaxy S2 smartphone in the domestic market next week.
Patent lawsuits are a regular occurrence among technology giants in the United States. Apple is currently embroiled in disputes with Finland's Nokia, Taiwan's HTC and US handset maker Motorola among others.
Explore further: Apple files suit against Samsung