Speaking at the Shangri-La defence forum in Singapore, Kallas was responding to comments by US Defense Secretary Pete Hegseth, who called President Donald Trump's insistence on more military spending "tough love".

"It's love nonetheless, so it's better than no love," Kallas quipped when asked later about Hegseth's speech.

Brussels' relationship with Washington was not broken, Kallas stressed, saying she spoke to Hegseth on Friday.

"You heard his speech. He was actually quite positive about Europe, so there's definitely some love there," she said.

Trump has consistently pressed NATO countries to increase defence spending, asking for as much as five percent of GDP and saying Washington will no longer tolerate freeloaders.

Kallas said "there are different countries in Europe and some of us have realised a long time ago that we need to invest in defence".

"The European Union has shifted gear and reimagined our own paradigm as a peace project backed up with hard defence," she said.

"It is a good thing we are doing more, but what I want to stress is that the security of Europe and the security of the Pacific is very much interlinked," she added.

Kallas pointed to Ukraine, where North Korean soldiers were already operating and China was providing military hardware to Russia.

"There were some very strong messages in the US secretary of defense speech regarding China," Kallas said.

"I think again, if you are worried about China, you should be worried about Russia," she said.

Kallas said the EU wanted to build "partnerships in our mutual interest" in the Indo-Pacific region, including in the field of defence and economy.

But the EU was also bringing economic power to the table, she said.

Kallas disagreed with suggestions that Washington should focus on the Indo-Pacific region and Europe concentrate on its own patch.

"I really think if you look at the economic might of China, I think... the big countries or the superpowers sometimes overestimate their own strength," she said.

China's economic dominance could only be tackled together with "like-minded partners like the United States, like the UK, Australia, New Zealand, Japan, and South Korea... and Singapore," said Kallas.

Speaking earlier, Hegseth told delegates "we're pushing our allies in Europe to own more of their own security to invest in their defence".

"Thanks to President Trump they are stepping up," he said.