Queen reflects on Chinese state visit
10 May 2016 Last updated at 22:15 BST
The Chinese President Xi Jinping's state visit last October was the topic of conversation when the Queen met a senior police officer, Commander Lucy D'Orsi.
Commander D'Orsi told the Queen it had been quite a testing time for her.
The conversation took place during a garden party at Buckingham Palace to celebrate the Queen's 90th birthday.