"Looking at President Xi standing alongside the leaders of Russia, Iran, North Korea in Beijing today, these aren't just anti-Western optics, this is a direct challenge to the international system built on rules," Kaja Kallas told journalists.

"It's not just symbolic. Russia's war in Ukraine is being sustained by Chinese support. These are realities that Europe needs to confront now."

Russia's Vladimir Putin and North Korea's Kim Jong Un flanked Xi at the event to mark the end of World War II, capping a week of diplomatic grandstanding by the Chinese president and his allies against the West.

In unprecedented scenes, Xi shook both their hands and chatted with the pair as they walked down a red carpet by Tiananmen Square, with Putin to Xi's right and Kim to his left.

"We are experiencing deliberate attempts to change the international order," Kallas said, in a subsequent speech.

"China and Russia also speak of leading changes together not seen in a hundred years and the revision of the global security order."

Kallas said that Europe needs to better flex its "geopolitical power" in the face of the global upheaval.

"A new global order is in the making," Kallas said.

"It will not be shaped without Europe, but it will be shaped by what Europe is willing to do, whether we are willing to recognise the need for Europe to play a geopolitical role."