China and Britain have signed trade deals worth over 14 billion pounds (US$24 billion) during a visit by Chinese Premier Li Keqiang that included a meeting with Queen Elizabeth II at Windsor Castle.

Britain pulled out all its ceremonial stops for Li, who is on a three-day visit to boost relations.

Business dominated yesterday's proceedings, with the two sides focusing on potential collaborations in nuclear power, high-speed railways and finance.

Prime Minister David Cameron announced the business deals, saying that Britain is a "strong and good friend of China and supporter of China's rise."

The two countries agreed to increase bilateral trade to US$100 billion in 2015.

No details were given of the agreements but China National Offshore Oil Corporation said yesterday it had signed a 20-year deal with British energy giant BP for supplies of liquefied natural gas.

Under the agreement, BP is to supply up to 1.5 million tons per year from its global portfolio to CNOOC over 20 years from 2019, the Chinese company said.

In Moscow, Bob Dudley, BP's chief executive, said: "It is a 20-year supply agreement on LNG. It is a fair price for them and a fair price for us. It is a good bridge between the UK and China in terms of trade."

Royal Dutch Shell also signed an accord with CNOOC yesterday.

Also on the table is a deal to make China Construction Bank, the country's second-largest lender, the first clearing service for offshore trading of the yuan in London.

London, which dominates the US$5-trillion-a-day global foreign exchange market, is seeking to fend off challenges to its position as the leading offshore yuan center in Europe.

Earlier, a military band played as Li and his wife Cheng Hong arrived at Windsor Castle to be greeted by the queen.

The Chinese leader then traveled to central London for a formal inspection of British soldiers and a meeting with Cameron at his office in Downing Street.

Cameron told reporters he and Li also discussed terrorism, Iraq and Ukraine, among other topics.

Li's trip to Britain is the first by a Chinese premier since Wen Jiabao visited in 2011.

China views Britain, the world's sixth largest economy and home to the only financial capital to rival New York, as Europe's most open place to do business. Li wrote in The Times newspaper on Monday that there were "many areas for collaboration" between the two countries.

He said he was hoping for "stronger cooperation in finance, infrastructure construction, among others."