BEIJING—Apple Inc. Chief Executive Tim Cook met with senior Chinese leader Li Keqiang this week, in the strongest signal yet that the company is strengthening ties in a market it long neglected.

The executive met with Mr. Li on Tuesday to discuss intellectual-property issues and greater cooperation, according to state media. In its evening news broadcast on Wednesday, state-run China Central Television showed Mr. Li meeting with Mr. Cook at Zhongnanhai, the closely guarded compound here that houses China's top leaders.

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