Brussels announced on Monday it was banning EU funding for Chinese-made inverters. Described as a "brain" for solar energy systems, inverters help connect renewable sources to the electricity grid.

The European Union has in recent years viewed China's dominance of the green tech sector with increasing suspicion and fears that the 27-country bloc's reliance on Chinese supply is a growing vulnerability.

"China urges the EU to immediately stop stigmatising China by designating it as a 'high-risk country' and to end its unfair and discriminatory practices against Chinese products," a Chinese commerce ministry spokesperson said in a statement.

The ban has been in place since early April and applies to new projects -- with some leeway granted to projects that have already advanced, an EU official said.

The policy applies to inverters coming from China, notably from firms such as Huawei and Sungrow, but also from Russia, Iran and North Korea, the official said.

"Among the most pressing threats is the risk of disruption of the EU's critical infrastructure by foreign actors," said EU spokeswoman Siobhan McGarry.

"In practice, this could mean a shutdown, a remote shutdown, of member states' networks, leading to countrywide blackouts," she said.

The EU plans to prioritise inverters made in Europe, or use suppliers from countries deemed to be more "like-minded", such as Japan, South Korea, the United States or Switzerland, the official said.

The Chinese commerce ministry statement said the ban will harm trade relations between China and the European Union, adding that Beijing "will take measures to protect the rights and legitimate interests of Chinese companies".