It would be an absolute "red line" if China provided weapons to Russia, a senior European Union official said on Friday (local time), adding that the EU would respond with sanctions.
The comments echo remarks by German Chancellor Olaf Scholz on Thursday warning Beijing against providing such aid to Moscow as it continues to fight in Ukraine.
"Don't deliver any weapons to the aggressor Russia," Scholz said in a speech to the German Parliament ahead of his meeting with US President Joe Biden in Washington later on Friday.