China's foreign ministry has joked that the millions of Chinese tourists arriving in Australia annually could make the government feel nervous if it treats them as spies.

The comments by Chinese foreign ministry spokeswoman Hua Chunying in Beijing came after the the Australian Security Intelligence Organisation (ASIO) told a parliamentary inquiry that the threat posed by foreign spying was worse than during the Cold War.

ASIO's deputy director for counter-espionage, Peter Vickery, said in Canberra on Wednesday, during hearings on the Turnbull government's foreign influence bill, that some countries posed an "extreme" threat, but declined to name them.

Ms Hua was asked in a press conference on Thursday about Australian media reports that China was listed as an "extreme threat" by ASIO.