China has overtaken Britain as a world power, a state-run newspaper argued scornfully Wednesday, after Premier Li Keqiang oversaw the signing of trade deals that will see Chinese invest in British high-speed trains and nuclear power.

"Britain's national strength cannot be placed in the same rank as China now, a truth difficult to accept for some Britons who want to stress their nobility," the state-run Global Times wrote in an editorial.

"Chinese society is more and more relaxed in dealing with Sino-UK ties, while the British could not be pettier," it added as Li began the third and final day of his British trip.

The newspaper, which is close to China's ruling Communist Party, frequently takes a nationalistic tone.

Britain and China signed trade deals worth more than 14 billion pounds ($24 billion, 17 billion euros), Prime Minister David Cameron announced Tuesday.

China will invest in Britain's new high-speed rail link from London to northern cities, and in new nuclear power plants among other energy projects, according to a joint statement. That could include Britain importing Chinese reactors.

The trend of investment illustrates dramatically how much China has changed: from economic basket-case a few decades ago to now being in a position to export advanced technology to the cradle of the Industrial Revolution.

"China is the largest developing country while Britain is the first industrialised nation, so further cooperation between the two would not only benefit themselves, but also the whole world," China's Xinhua news agency quoted Li as saying.

Among other trade deals, British energy giant BP says it will sign a pact worth around $20 billion to supply China with liquefied natural gas. And Royal Dutch Shell signed a comprehensive cooperation agreement with Chinese energy giant CNOOC.

Li and Cameron have been working to repair a relationship that had suffered after a spat over Tibet.

But the improved mood was strained last week when The Times newspaper reported that Beijing had made a meeting between Li and Queen Elizabeth II a precondition for the visit, threatening to call it off otherwise.

The Global Times dismissed such reports as "hype" which "only serves to reflect the narrow-mindedness of the British media and even the whole of its society".

"The once-powerful British Empire must now resort to such trickery to manifest its pride," it said.

"Perhaps Chinese people should forgive Britain's confusing sentiment," it continued. "A rising country should understand the embarrassment of an old declining empire and at times the eccentric acts it takes to hide such embarrassment."