Chinese President Xi Jinping slammed the European Union's plan for a carbon tax system Friday in a call with the leaders of France and Germany, state media reported.

The European Parliament on Wednesday endorsed the creation of a carbon border tax that would shield EU companies from cheaper imports from countries with weaker climate policies.

The scheme is seen as a key part of the EU's Green Deal, an ambitious push to achieve carbon neutrality by 2050 and meet the targets of the Paris Climate Agreement.

"Tackling climate change is a shared responsibility... and should not become a geopolitical bargaining chip or used to attack other countries (or impose) trade barriers," Xi told France's Emmanuel Macron and Germany's Angela Merkel on the sidelines of a virtual climate summit Friday, according to state broadcaster CCTV.

Xi also urged developed countries to "set an example in reducing emissions" and help poorer nations to deal with the fallout from the climate crisis by sharing technology and increasing funding for green projects.

China last year announced bold plans to peak carbon emissions before 2030 and become carbon-neutral by 2060.

Transitioning from a carbon peak to carbon neutrality in three decades would be "a tough battle", Xi said.

The Chinese leader's comments come as US climate envoy John Kerry is in Shanghai to drum up support from the world's biggest polluter for America's drive to address environmental challenges.

Kerry is in China for meetings with his counterparts until Saturday -- the first visit by an official from the new US administration.

The main purpose of his travels to China and elsewhere is to rally support for a virtual climate summit hosted by US President Joe Biden next week. China has not announced whether Xi will participate.

China in recent years has taken over the mantle of global climate leadership left vacant when former US president Donald Trump withdrew from the Paris agreement to address the catastrophic effects of global warming.

The US has rejoined the international accord under Biden's administration, that has also pledged to reduce emissions.

Each year, the world's two biggest economies spew out more than half of the greenhouse gases linked to global warming.

While Beijing and Washington have clashed over Hong Kong and Xinjiang, the climate issue is seen as a shared interest which cuts through the rancour.