Apple Inc.’s top executive overseeing its Siri virtual assistant told staff that delays to key features have been ugly and embarrassing, and a decision to publicly promote the technology before it was ready made matters worse.

Apple CEO Tim Cook said in the spring that his company had all kinds of big AI plans. Many of them have yet to materialize.

Apple is reassuring employees on the Siri team who may be feeling demotivated by the recent Siri delays and the bad press surrounding