SEOUL: Samsung said Thursday that unexpectedly high demand for its latest flagship smartphone, the Galaxy S4, was behind shipping issues that delayed scheduled sales in the US market.

“We are experiencing difficulty in boosting supply in the short term because pre-order demand has been far stronger than we anticipated,” said Lee Don-Joo, head of sales and marketing at Samsung’s mobile unit.

US telecom carriers T-Mobile and Sprint both had to postpone scheduled sales of the S4, citing delays in shipments from the South Korean consumer electronics giant.

The world’s top handset maker starts selling the much-anticipated device in South Korea on Friday, followed by a global roll-out at the weekend.

The S4, armed with eye motion control technology that will pause a video when the user looks away, comes with a faster chip and is thinner and lighter than the previous S3 model.

It features a high-definition, five-inch (12.7-centimetre) screen, enhanced picture-taking capabilities and the capacity to translate to and from nine languages. It also recognises touch by users wearing gloves.

The device was unveiled last month at a glitzy event at New York’s Radio City Music Hall — reflecting Samsung’s desire to expand its presence in the high-end US market against arch rival Apple and its iconic iPhone.

After years of following and refining the iPhone’s pioneering innovations — a strategy that resulted in bitter patent battles with Apple — Samsung has dethroned Apple to become the world’s top smartphone maker.

Samsung did not give a sales target at a press event Thursday, but Kim said he anticipated global sales would “outpace” those of the popular S3.

Back in January, Samsung said it had shifted more than 41 million Galaxy S3 units since its market debut last May. Analysts and market observers estimate that figure is now close to 60 million units.

The S4 release has been preceded by a massive promotional campaign — from the launch in New York to lighting up the sails of Sydney’s iconic opera house on Tuesday.