China on Wednesday ordered four US news outlets to disclose details of their staff and financial operations in the country within seven days, as a media row escalates between Washington and Beijing.

The Associated Press, United Press International, CBS and NPR must report the information -- as well as details of any real estate they hold in China -- in retaliation for Washington's crackdown on four Chinese state media outlets, foreign ministry spokesman Zhao Lijian said.

China's actions are "entirely necessary countermeasures against the United States' unreasonable oppression of Chinese media organisations in the US", Zhao said at a regular press briefing.

The US State Department on June 22 reclassified four Chinese state media outlets as foreign missions in the United States, adding to five others designated in February.

All nine outlets "are effectively controlled by the government of the People's Republic of China", State Department spokeswoman Morgan Ortagus said in June.

After the first group of outlets were ordered to cut their Chinese staff working in the United States, Beijing hit back by expelling more than a dozen US nationals working for The New York Times, The Wall Street Journal and The Washington Post.

Beijing also ordered the papers, as well as Voice of America and Time magazine, to declare in writing their staff, finances, operations and real estate in China.

Zhao on Wednesday said the US restrictions on Chinese media "exposed the hypocrisy of the so-called press freedom touted by the US".

China urged the US to "correct its mistakes and stop the political suppression and unreasonable restrictions on Chinese media", Zhao said.

All nine Chinese state-run news organisations are required to report details of their US-based staff and real estate transactions to the State Department. Their news reporting will not be restricted, US officials said in June.

The Associated Press and NPR said in separate statements that they were reviewing Wednesday's request from Beijing.

'More and more angry'

Relations between Beijing and Washington have worsened as the two sides trade barbs over blame for the COVID-19 pandemic and human rights violations.

The United States has led a global backlash against a national security law imposed on Hong Kong by Beijing Tuesday, cutting off defence exports and revoking the financial hub's special trade status.

US President Donald Trump said on Tuesday he was growing "more and more angry at China" over the pandemic, which he blames on Chinese inaction and lack of transparency.

Meanwhile, China has accused the Trump administration of politicising the pandemic to deflect from its own handling of the crisis.

US Secretary of State Mike Pompeo met senior Chinese official Yang Jiechi in Hawaii last month, with little apparent effect on soaring bilateral tensions.