China tightened the rules on a number of US media outlets on Monday, in a move it said was "necessary and reciprocal" after Chinese journalists in America were hit with restrictions last week.

The world's two largest economies, sparring over issues from trade and technology to human rights, have restricted visas for each other's reporters, while China has expelled journalists.

After the US declared several more Chinese media outlets to be "foreign missions", Beijing late Monday demanded that six US media groups report to the government about their staffing, finances and real estate.

They included the LA Times, Newsweek and the American Broadcasting Corporation.

Foreign ministry spokesman Zhao Lijian said in a statement that the requirements were "legitimate and justified self-defense in every sense".

"What the United States has done is exclusively targeting Chinese media organizations driven by the Cold War mentality and ideological basis," Zhao added.

The moves are the latest in a series of tit-for-tat measures between Beijing and Washington.

Last week the US designated a further six Chinese media organisations as propaganda outlets that answer to the state.

It was the third round of US designations of Chinese outlets as foreign missions, which requires that they report details on their US-based staff and real estate transactions to the State Department.

The department earlier imposed rules on nine outlets including the official Xinhua news agency and China Global Television Network.

China has denounced the regulations and retaliated by expelling US citizens who work for major news organisations, including The New York Times, The Washington Post and The Wall Street Journal.

In May the US shortened the visa for Chinese journalists in the US to 90 days, and last month the Foreign Correspondents' Club of China said Beijing was no longer renewing press credentials for US media employees in the country.

China