Apple’s top artificial intelligence executive is stepping down and will retire in 2026, the company announced Monday.

John Giannandrea had been at Apple since 2018, where his official title was senior vice president for machine learning and AI strategy.

He will be replaced by Amar Subramanya, who comes to Apple after a brief stint as corporate vice president of AI at Microsoft and more than a decade at Google.

Subramanya will report to one of CEO Tim Cook’s deputies, Craig Federighi, rather than to Cook directly, as Giannandrea had.

“AI has long been central to Apple’s strategy, and we are pleased to welcome Amar to Craig’s leadership team and to bring his extraordinary AI expertise to Apple,” Cook said Monday.

The abrupt change at a company known for its careful succession planning highlights Apple’s challenge as it tries to compete with top AI developers such as Google, ChatGPT owner OpenAI, Meta and Microsoft.

Earlier this year, Apple delayed the release of an upgraded version of Siri with AI powered features. At the time, it said it was going to “take us longer than we thought” to develop the new version.

The company said it anticipated rolling out new features “in the coming year,” but it has not offered any more specifics.

“We’re making good progress on it, and, as we’ve shared, we expect to release it next year,” Cook said on the company’s quarterly earnings call in late October.

“With Apple Intelligence, we’ve introduced dozens of new features that are powerful, intuitive, private and deeply integrated into the things people do every day,” Cook said on the Oct. 30 call

The company is targeting the spring to release the upgraded Siri, Bloomberg News recently reported.

While Apple’s iOS and macOS are integrated with ChatGPT, those features are somewhat limited.

In recent weeks, Apple has reportedly neared deals to integrate with Google’s Gemini, as well as AI models from Perplexity and Anthropic.

Apple’s stock has also felt the effect of what some perceive to be its lagging AI services.

This year, Apple shares have returned 13%, which tops both Amazon and Microsoft. But shares of Oracle have popped 20%, Nvidia has surged 34%, and Google parent company Alphabet has soared 65%.

Still, Apple remains the world’s second-largest publicly traded company, with a market value of $4.2 trillion, behind only Nvidia.

Overall, the S&P 500 has risen almost 16% this year.

Steve Kopack is a senior reporter at NBC News covering business and the economy.