China trying to influence public opinion in US and its allies: Bolton

China is trying to influence public opinion in the US and countries like Australia that are America's allies, a top White House official alleged Sunday.

"The massive Chinese effort to influence public opinion is not just confined to the United States. They're doing it in Australia, other countries, close friends of ours, US National Security Advisor John Bolton told ABC news.

So this really goes to the core of how you maintain a free and open society in this country, when other countries are trying to influence it the way that China has. It goes well beyond just election hacking, although we certainly have been concerned about China doing that as well, Bolton said.

He said the development is "worrisome".

This is an effort by China to influence opinion in America that makes the election hacking we have been talking about by Russia -- look, as one senior US official in intelligence called it, the JV effort, he noted.

What China's doing what, Vice President Pence explained some months back in a very important speech about these efforts, really is far greater in magnitude than any other foreign effort we have seen in history to influence American opinion, he said.