The top US intelligence official says China is the "greatest threat to democracy and freedom" since World War Two.

Writing in the Wall St Journal, John Ratcliffe said China was growing its power by stealing US secrets and then replacing US firms in the market.

The Trump administration has taken a hard line on China, imposing tariffs on Chinese goods and accusing Beijing of intellectual property theft.

China has not yet responded.

However, it has responded forcefully to US moves such as the imposition of tariffs and efforts to keep the telecoms giant Huawei out of the American market.

Beijing was preparing for confrontation with the US and intended to dominate the world "economically, militarily and technologically", Mr Ratcliffe warned.

Some of Mr Ratcliffe's comments echo previous interventions by Secretary of State Mike Pompeo and FBI chief Christopher Wray.

However, they also come at a time when China has stepped up pressure on US ally Australia, publishing a list of ways it wants Canberra to change its behaviour, slapping tariffs on imports of Australian wine and provoking the Australian government over its rights record in Afghanistan.

Chinese foreign ministry spokeswoman Hua Chunying had earlier on Wednesday accused the US of "launching various political oppressive campaigns against China", adding that this came "out of strong ideological bias and a strategy to contain China".

"There is a Chinese saying... 'the eye sees what the mind believes'," she said in her daily press conference. "We hope the US will... stop regarding everyone as spies."
What did Ratcliffe say?

The Director of National Intelligence said China had replaced Russia and counter-terrorism as the main focus of US intelligence activities.

China was engaged in a form of economic espionage that he described as "rob, replicate and replace" - giving the example of a Chinese wind turbine firm that was found guilty in the US of stealing from a US competitor before going on to sell worldwide while the US firm lost shareholder value and fired staff.

US intellectual property worth $500bn (£370bn) was being stolen every year, he said. FBI arrests of Chinese nationals for stealing research had become frequent and China had also been paying the head of Harvard University's chemistry department $50,000 a month until his arrest earlier this year.

Mr Ratcliffe also accused Chinese intelligence services of introducing vulnerabilities into technology offered by top Chinese tech firms such as Huawei and said allies using Chinese technology would not have US intelligence shared with them.

He said US intelligence showed that China had carried out "human testing" on troops with the aim of developing soldiers with "biologically enhanced capabilities".

And he said China had engaged in a "massive influence campaign" targeting US members of Congress and their staff by encouraging unions at big firms to tell local politicians to take a softer line on China or face losing union members' votes.

Beijing was targeting members of Congress with "six times the frequency of Russia and 12 times the frequency of Iran", Mr Ratcliffe said.

Other countries faced the same challenge from China as the US, he said. "China believes that a global order without it at the top is a historical aberration," he said. "It aims to change that and reverse the spread of liberty around the world."
How has the Trump White House handled China?

Under President Trump, the US has ramped up confrontation with China in a number of areas.

The two countries have imposed tariffs on hundreds of billions of dollars worth of one another's goods and imposed export controls on products in sensitive areas.

On Thursday the White House said it had added four more Chinese firms - chipmaker SMIC, national oil firm CNOOC, China Construction Technology Co and China International Engineering Consulting Corp - to a blacklist of firms deemed to be linked to the Chinese military.

Earlier this year the US ordered a Chinese consulate in Houston to close over economic espionage concerns - Beijing responded by ordering the US to close its consulate in the city of Chengdu. The two countries have also expelled each others' journalists.

Relations between the two superpowers have also soured over the coronavirus pandemic - which Mr Trump has repeatedly referred to as the "Chinese virus" - and China's moves in Hong Kong.

Mr Trump signed an order ending preferential US treatment for Hong Kong after Beijing imposed a controversial new security law there, which the US said ended Hong Kong's autonomy.

The US has also accused China of "horrific and systematic" human rights abuses in its treatment of its Muslim Uighur minority in the Xinjiang region and has sanctioned some Chinese politicians.

China is accused of mass detentions, religious persecution and forced sterilisation of Uighurs and others, but Beijing denies any mistreatment.

Will Biden take a different approach?

President-elect Joe Biden, who takes office in January, is expected to continue President Trump's policy of countering China, but jointly with allies, as opposed to Mr Trump's preference for unilateral trade deals.

There is rare cross-party agreement on getting tough with China over trade and other issues, the BBC's White House correspondent Tara McKelvey says.

The Trump administration has been successful in winning global support for a boycott of Chinese communications technology.

However, Mr Biden is likely to be more active in seeking areas of co-operation with a rising China, particularly in areas such as climate change.