US officials believe China covered up the extent of the coronavirus outbreak – and how contagious the disease is – in order to stock up on medical supplies needed to respond to it, intelligence documents show.

Chinese leaders "intentionally concealed the severity" of the pandemic from the world in early January, according to a four-page Department of Homeland Security report dated May 1 and obtained by The Associated Press.

The revelation comes as the Trump administration intensified its criticism of China, with Secretary of State Mike Pompeo saying today that China was responsible for the spread of disease and must be held accountable.

The sharper rhetoric against China coincides with administration critics saying the government's response to the virus was inadequate and slow.

President Donald Trump's political opponents have accused the president and his administration of lashing out at China, a geopolitical foe but critical US trade partner, in an attempt to deflect criticism at home.

The analysis states that, while downplaying the severity of the coronavirus, China increased imports and decreased exports of medical supplies.

It attempted to cover up doing so by "denying there were export restrictions and obfuscating and delaying provision of its trade data", the analysis states.

The report also says China held off informing the World Health Organisation that the coronavirus "was a contagion" for much of January so it could order medical supplies from abroad – and that its imports of face masks and surgical gowns and gloves increased sharply.

Those conclusions are based on the 95 percent probability that China's changes in imports and export behavior were not within normal range, according to the report.

Mr Trump has speculated that China could have unleashed the coronavirus due to some kind of horrible "mistake".

His intelligence agencies say they are still examining a notion put forward by the president and aides that the pandemic may have resulted from an accident at a Chinese lab.

Speaking Sunday on ABC America's "This Week", Mr Pompeo said he had no reason to believe that the virus was deliberately spread.

But he added, "Remember, China has a history of infecting the world, and they have a history of running substandard laboratories".

Coronavirus: what you need to know

What is the difference between COVID-19 and the flu?

The symptoms of COVID-19 and the flu are very similar, as they both can cause fever and respiratory issues.

Both infections are also transmitted the same way, via coughing or sneezing, or by contact with hands, surfaces or objects contaminated with the virus.

The speed of transmission and the severity of the infection are the key differences between COVID-19 and the flu.

The time from infection to the appearance of symptoms is typically shorter with the flu. However, there are higher proportions of severe and critical COVID-19 infections.

What is social distancing?

Social distancing involved minimising contact with people and maintaining a distance of over one metre between you and others.

When practicing social distancing, you should avoid public transport, limit non-essential travel, work from home and skip large gatherings.

It is okay to go outdoors. However, when you do leave home, avoid touching your face and frequently wash your hands.

For breaking news alerts and livestreams straight to your smartphone sign up to the 9News app and set notifications to on at the App Store or Google Play. You can also get up-to-date information from the Federal Government's Coronavirus Australia app, available on the App Store, Google Play and the Government's WhatsApp channel.

Reported with Associated Press.

Source: 9News https://www.9news.com.au/world/china-reportedly-hid-coronavirus-severity-to-hoard-supplies/23bbd517-e6f5-479d-9bed-c8b903b1eedc