The latest iPhone is at the centre of controversy already - the day after it was unveiled.

Technology firm Samsung is planning legal action to stop Apple selling it in two European countries and it has received a lukewarm reception from experts.

The iPhone 4S looks identical to the previous iPhone 4 and shares its glass front and back and trademark stainless steel band, but has a new more powerful A5 chip inside and potentially revolutionary voice recognition software.

South Korean-based Samsung released a statement today saying it planned “to file separate preliminary injunction motions in Paris, France and Milan, Italy requesting the courts block the sale of Apple’s iPhone 4S in the respective markets”.

It claims the design infringes technology patents and said Apple has “continued to flagrantly violate our intellectual property rights”.

It also said it plans similar moves in other countries “after further review”.

An Apple spokesman said the firm would not be commenting on the claims.

The phone will go on sale in the UK on October 14 - the same day as the United States.

It was unveiled at a press conference in California yesterday - which was screened live in the Apple store in Covent Garden, central London.

It was the company’s first major product launch in years without Steve Jobs.

New CEO Tim Cook took over after Mr Jobs, who has been battling health problems, resigned from the post in August.

He was joined by senior vice president of iPhone software Scott Forstall, who showed off the voice recognition software, called Siri, which allows users to ask the phone questions and get answers.

He said it works as “your humble, intelligent personal assistant that goes everywhere with you and can do anything for you just by asking”.

Mr Forstall said Siri understood the language and context of users’ questions and then gave a series of examples by asking the phone a series of questions.

He said: “I’ve been in the AI (artificial intelligence) field for a long time and this still blows me away.”

Technology expert Ernest Doku, of uSwitch.com, said some people would be “bitterly disappointed” at the announcement of an upgraded phone rather than a brand new model.

He added: “A phone which talks to you and answers your questions? That’s the iPhone 4S. Slightly disappointing from a hardware standpoint, but Siri has the potential to revolutionise how we use our mobiles.

”Apple is gambling that people will see this as a reinvention of the wheel.”

Nate Lanxon, editor of Wired.co.uk, said: “It’s more of an evolution I think, hardware wise, than a revolution. A lot of people were expecting the iPhone 5, they were expecting a whole new design and really what they got was a phone that sort of already exists but with lots and lots of improvements.”

The phone has an eight megapixel camera and also allows users to take HD video.

The 64 gigabytes phone will sell in the United States for 399 US dollars (£260), the 32GB version for 299 US dollars (£195) and the 16GB phone for 199 US dollars (£130).