BEIJING (BLOOMBERG) - China has denounced US efforts to stop ASML Holding and Nikon from selling key chipmaking technology to the country as "technological terrorism".

Chinese Foreign Ministry spokesman Zhao Lijian criticised the export curbs sought by Washington during a regular news briefing on Wednesday (July 6) in Beijing.

He did not elaborate on whether China planned any response to the move.

Washington's proposed restrictions on ASML would expand an existing moratorium on the sale of the most advanced systems to China, in an attempt to thwart China's plans to become a world leader in chip production.

If the Netherlands agrees, it would broaden significantly the range and class of chipmaking gear now forbidden from heading to China, potentially dealing a serious blow to Chinese chipmakers from Semiconductor Manufacturing International to Hua Hong Semiconductor.

American officials are lobbying their Dutch counterparts to bar ASML from selling some of its older deep ultraviolet lithography systems, sources said.

These machines are a generation behind cutting-edge ones but are still the most common method in making certain less advanced chips required by cars, phones, computers and even robots.

American officials are also trying to exert pressure on Japan to stop shipping the same technology to Chinese chipmakers, one of the sources said.

Japan's Nikon competes with ASML in the area.