China's President has delivered a message to Britain at a state banquet held in his honour: "Opportunity may knock just once - grab it before it slips away."
The Queen hosted the event for Xi Jinping and his wife Madame Peng Liyuan at Buckingham Palace on the first full day of his state visit to Britain.
Prime Minister David Cameron, Labour leader Jeremy Corbyn and the Duke and Duchess of Cambridge were among 170 guests dining on fillets of West Coast turbot and Balmoral venison at the white-tie dinner.
As the Queen introduced the Chinese President, she hailed the "milestone" of his four-day visit to Britain and declared Anglo-Chinese ties are being taken to "ambitious" new heights.
Speaking in Mandarin, Mr Xi told attendees: "With growing interdependence and interwoven interests, countries in the world are increasingly becoming a community of shared future.
"As an old Chinese adage goes, 'Opportunity may knock just once, grab it before it slips away'.
"In Britain, you also have a famous saying, 'A wise man turns chance into good fortune'.
"As China-UK comprehensive strategic partnership enters the second decade this year, let us seize the opportunity and work together to usher in an even brighter future for China-UK relationship."
He delivered a similar message when he addressed MPs and peers at the Houses of Parliament earlier in the day.
"It is fair to say that China and the UK are increasingly interdependent and becoming a community of shared interests," Mr Xi said in his 11-minute address in the opulent Royal Gallery.
David Cameron earlier hailed a new "golden era" in UK-Chinese relations, saying €41bn worth of trade and investment deals will be completed during his visit.
Mr Xi's first full day in Britain was filled with pomp and pageantry, including a ceremonial welcome at London's Horse Guards Parade and a glittering carriage procession to Buckingham Palace.
But he was not given a warm reception by all - human rights protesters clashed with pro-China supporters lining the Mall during the procession.
And Labour MPs have been urging the Government to tackle Mr Xi over Chinese steel firms flooding European markets with cheap steel.
Mr Corbyn raised both China's human rights record and the impact of its exports on the steel industry in direct talks with Mr Xi before the banquet.
The party said their discussions were "cordial and constructive".
Foreign Minister Philip Hammond told Sky News the steel issue would be addressed during visit and denied Britain was in a "master/servant" relationship with China.
