Douglas MacMillan
Bloomberg News

Apple Inc. Chief Executive Tim Cook says television is an area of “intense focus” for the company as it seeks to build on the success of Macs, iPhones and iPads.

“We’re going to keep pulling this string and see where it takes us,” Cook said in an onstage interview at the D10 conference in Rancho Palos Verdes, Calif.

Apple co-founder Steve Jobs, who he died last year, told his biographer that he had “finally cracked” how to build a TV with a simple user interface that would wirelessly synchronize content with Apple’s other devices.

The company is working on a television that could be unveiled this year and released in 2013, according to Gene Munster, an analyst at Piper Jaffray Cos.

Apple turned to Jeff Robin, the software engineer who built the iTunes media store and helped create the iPod, to lead its development of a TV set, people with knowledge of the product said last year.

The company sells a set-top box called Apple TV that lets customers stream video from Apple products or the Internet to their TVs. Still, that device has yet to gain wide acceptance, and Apple executives have called it a “hobby.”

During the conference, put on by the AllThingsD technology blog, Cook said that Apple has “great appreciation” for Facebook Inc., the largest social-networking service.

“The relationship is very solid,” he said. “We have great respect for them. I think we can do more with them. Stay tuned on this one.”

Cook said Apple remains interested in acquisitions, though it’s not seeking a large deal. He said it’s possible that more manufacturing of his company’s products will happen in the United States.

The iPhone, Apple’s best-selling device, might one day be assembled in the U.S., he said.

Much of the manufacturing and assembly of Apple products takes place in factories in Asia, which have come under criticism for treatment of workers. Cook said the company is moving toward greater transparency in supplier responsibility and environmental sustainability.

Even as the company discloses more in those areas, it will redouble efforts to keep products under wraps while they are still under development, Cook said.

Responding to criticism that Apple’s Siri voice-recognition service has functioned improperly for some users, Cook said Apple is working to improve the technology.

“There’s more that it can do, and we have a lot of people working on this, and I think you’ll be really pleased with some of the things that you’ll see over the coming months,” Cook said.

Cook also said that the company’s iAd online advertising effort wasn’t essential to Apple’s future, which would remain centered on hardware.

“When I was talking about the things at Apple that make up the four legs of the stool, I didn’t mention that one,” Cook said, referring to Macs, iPods, iPhones and iPads.

Before becoming chief executive last year, Cook was Apple’s chief operating officer, leading the company’s vast supply chain. He joined the company in 1998 from Compaq Computer Corp. and was instrumental in managing the operational side of Apple’s business while longtime Chief Executive Jobs concentrated on product development and marketing.

The company’s gross margins of 47 percent last quarter are more than double those of rivals Hewlett-Packard and Dell.

In June, at Apple’s annual Worldwide Developers Conference, the company is slated to unveil a new lineup of Mac laptops, as well as show off new features for the latest mobile operating system that powers the iPad and iPhone, people with knowledge of the matter have said.

A new iPhone, which accounts for more than half the company’s sales, is expected to be unveiled by October, according to analysts, including Munster.