He described the rising superpower's tactics as a blatant breach of international law and declared France stood with Australia.

Mr Macron offered the public backing after welcoming Prime Minister Scott Morrison to Paris on Tuesday.

"You are at the forefront of the tensions that exist in the region, of the threats, and sometimes of the intimidation, and I want to reiterate here how much we stand by your side," he said.

"I would like to reiterate how committed France remains to defending the balance in the Indo-Pacific region and how much we consider the partnership we have with Australia is essential in the Indo-Pacific strategy."

Mr Macron said the instability required a global response.

"We firmly reject any coercive economic measures taken against Australia in flagrant violation of international law," he said.

Mr Morrison described Australia and France as good friends and partners.

"No one understands liberty more than the French," he told reporters.

"Affinity is the word we use to describe our partnership - an affinity across so many areas of the relationship.

"Every element of our partnership is about reinforcing the values and beliefs we hold dearly."

Earlier, British Prime Minister Boris Johnson also backed Australia in its struggle with China.

"We stand shoulder to shoulder with our friends," Mr Johnson told reporters in London.

"But I probably speak for Scott as well when I say nobody wants to descend into a new Cold War with China - we don't see that as the way forward.

"This is a difficult relationship where it is vital to engage with China in as positive a way as we can."

Asked what behaviours concerned him the most, Mr Johnson highlighted China's human rights record in Hong Kong and Xinjiang, and its behaviour towards Australia and other regional neighbours.

China has launched trade strikes against more than $20 billion worth of Australian exports in response to a range of political grievances.

The strong comments from the British and French leaders come after the G7 summit condemned Beijing for its human rights record and "non-market policies and practices" that undermine the global economy.

Chinese Foreign Ministry spokesman Zhao Lijian described the G7 statement as deliberate slander and meddling.

"Such moves seriously contravenes the purposes and principles of the UN charter and the trend of the times for peace, development and win-win cooperation," he said.

"It reveals the malign intentions of the US and a few other countries to create confrontation and widen differences and disputes.

"China is strongly dissatisfied with and firmly opposed to this."

He said issues relating to Xinjiang, Hong Kong and Taiwan were "purely China's internal affairs that brook no foreign interference".

Mr Zhao was equally aggrieved by a statement released after a NATO summit in Brussels, which said China posed systemic challenges to the international order and the alliance's security.

Australian Associated Press