Beijing issued a harsh rebuke of Western critics who accuse China of using soft power as a vehicle to infiltrate other countries, as it kicked off its biggest political event of the year on Friday.

The country's top advisory body, the Chinese People's Political Consultative Conference, hit out against depictions of its campaign to build a positive global image as "sharp power", a term describing the way authoritarian states project influence abroad.

"It is not the first time that people have tried to smear China, and it will not be the last time," Wang Guoqing, CPPCC spokesman, said at a briefing in Beijing ahead of the opening of its annual session on Saturday.

"When other countries engage in cultural exchanges, they are showing soft or smart power, but when it comes to China, it's sharp power with motives.

"It is natural that we want to showcase our own image. Sadly, some Westerners may have physically entered the 21st century, but their mindset remains stuck in the cold war era."

It follows growing wariness over Chinese money and influence around the world, which US think tank the National Endowment for Democracy called an example of "sharp power". In Australia in particular, tensions have risen over suspicions that Beijing is wielding outsized influence in the country, with Prime Minister Malcolm Turnbull saying in December it would "stand up" against it.

Last month, FBI director Christopher Wray said US law enforcement was "watching warily" the activities of Confucius Institutes - Chinese government-funded educational and cultural centres in the United States and other countries.

Meanwhile, New Zealand's Prime Minister Jacinda Ardern ordered intelligence agencies to investigate claims of Beijing's political influence in the country.

Wang also took the opportunity to warn Japan against seeing China as its competitor in response to a question from a Japanese reporter - the sole foreign journalist to be called on during Friday's press conference. Despite improving relations between the two countries, they have historically been at odds over security issues such as territorial disputes in the East China Sea and Japan's close friendship with the US.

"A country who cannot face history and sees its neighbours as strategic adversaries will have no future," Wang said. "China noticed the positive signals released by Japan recently and hopes Sino-Japan relations will get back on track."