Visiting Chinese President attends a traditional ceremonial welcome held by British Queen Elizabeth II in London, capital of Britain, Oct. 20, 2015. (Xinhua/Rao Aimin)

Visiting Chinese President Xi Jinping (2nd L, front), his wife Peng Liyuan (2nd R, front), British Queen Elizabeth II (1st L, front), and Prince Philip (1st R, front) attend a traditional ceremonial welcome in London, capital of Britain, Oct. 20, 2015. (Xinhua/Pang Xinglei)

Chinese President Xi Jinping, accompanied by Prince Philip, inspects the guard of honor during a traditional ceremonial welcome held by British Queen Elizabeth II at the Horse Guards Parade in London, Britain, Oct. 20, 2015. (Xinhua/Pang Xinglei)

Chinese President Xi Jinping, accompanied by Prince Philip, inspects the guard of honor during a traditional ceremonial welcome held by British Queen Elizabeth II at the Horse Guards Parade in London, Britain, Oct. 20, 2015. (Xinhua/Rao Aimin)

Chinese President Xi Jinping (C), accompanied by Prince Philip (R, front), inspects the guard of honor during a traditional ceremonial welcome held by British Queen Elizabeth II at the Horse Guards Parade in London, Britain, Oct. 20, 2015. (Xinhua/Pang Xinglei)

Chinese President Xi Jinping and British Queen Elizabeth II ride a carriage to Buckingham Palace in London, Britain, Oct. 20, 2015. Xi attended a traditional ceremonial welcome held by the Queen at the Horse Guards Parade in London on Tuesday. (Xinhua/Rao Aimin)

Chinese President Xi Jinping and his wife Peng Liyuan, accompanied by British Queen Elizabeth II and Prince Philip, ride carriages to Buckingham Palace in London, Britain, Oct. 20, 2015. Xi attended a traditional ceremonial welcome held by the Queen at the Horse Guards Parade in London on Tuesday. (Xinhua/Zhou Lei)

Chinese President Xi Jinping (2nd R) and his wife Peng Liyuan (1st R) meet with British Prince Charles (2nd L) and his wife Camilla,Duchess of Cornwall,in London, Britain, Oct. 20, 2015. (Xinhua/Xie Huanchi)

Chinese President Xi Jinping (R) meets with British Prince William in London, Britain, Oct. 20, 2015. (Xinhua/Zhang Duo)

Chinese President Xi Jinping addresses both Houses of British Parliament in London, Britain, Oct. 20, 2015. (Xinhua/Ju Peng)

Chinese President Xi Jinping addresses both Houses of British Parliament in London, Britain, Oct. 20, 2015. (Xinhua/Ju Peng)

Chinese President Xi Jinping addresses both Houses of British Parliament in London, Britain, Oct. 20, 2015. (Xinhua/Zhang Duo)

Chinese President Xi Jinping (1st R) attends a banquet held by British Queen Elizabeth II (2nd R) at the Buckingham Palace in London Oct. 20, 2015. (Xinhua/Ju Peng)

Chinese President Xi Jinping (L) meets with British Labor leader Jeremy Corbyn in London Oct. 20, 2015. (Xinhua/Yao Dawei)