Apple Inc. has announced that John Ternus, the company's senior vice president of hardware engineering, will succeed Tim Cook as chief executive officer. The transition timeline was not immediately specified in the announcement.

Ternus, who has been with Apple for over two decades, currently oversees the development of the company's hardware products including the iPhone, iPad, and Mac lines. He joined Apple in 2001 and has played a key role in the engineering and development of many of the company's flagship devices.

The incoming CEO will inherit many of the same strategic challenges that Cook has navigated during his tenure, which began in 2011 when he took over from company co-founder Steve Jobs. These include maintaining Apple's position in the competitive smartphone market, expanding services revenue, and managing the company's complex global supply chain.

Cook, who has led Apple through significant growth and expanded its market capitalization to become one of the world's most valuable companies, has not announced his departure date. Under his leadership, Apple launched new product categories including the Apple Watch and expanded into services like streaming and financial products.

Ternus will take the helm at a time when Apple faces ongoing challenges including regulatory scrutiny in multiple markets, intensifying competition in key product segments, and the need to innovate in emerging technology areas. The company's stock performance and market position will likely be closely watched as the leadership transition unfolds.