Beijing on Friday lashed out at a claim by the US intelligence chief that China is the "greatest threat to democracy and freedom worldwide", calling it a "hodgepodge of lies".

The war of words comes as relations between the two superpowers have spiralled to their lowest point in decades and as Washington unveiled travel restrictions for members of the Chinese Communist Party.

US Director of National Intelligence John Ratcliffe said in a Wall Street Journal opinion piece on Thursday that Chinese spies were using economic pressure to influence or undermine US legislators.

"The People's Republic of China poses the greatest threat to America today, and the greatest threat to democracy and freedom worldwide since World War II," he wrote.

Beijing hit back angrily on Friday.

"[Ratcliffe] only continues to repeat lies and rumours to slander and discredit China, and wantonly play up the Chinese threat," said Chinese foreign ministry spokeswoman Hua Chunying.

"I think this is yet another hodgepodge of lies that the US government has been cooking up lately."

Hua also accused the US of being "engaged in a Cold War mindset, advocating major power competition, and wantonly expanding its nuclear weapons arsenal".

The world's two biggest economies have traded blows over the coronavirus pandemic, trade and technology competition, espionage, human rights and media freedoms under US President Donald Trump's tenure.

The US has repeatedly stressed that China is a grave threat to national security and Western democratic values, while China has accused the US of seeking to contain its rise through unlawful means.

Under the new US travel rules, visas issued to party members and their immediate family will remain valid for just one month, and for a single entry.

Previously some visas were issued that permitted unlimited entries and could remain valid for as long as 10 years.

The United States shut down the Chinese consulate in Houston in July, calling it a centre of espionage and harassment of Chinese nationals in the US.

In retaliation Beijing ordered the US to vacate its consulate in Chengdu.

Hua on Friday called for the United States to "stop damaging US-China relations and US-China mutual trust and cooperation".