Foreign ministers from NATO member statesmet in Brussels on Thursday just hours after US President Donald Trump sparked anger among allies with a new sweeping round of tariffs.

Relations between the US and its NATO allies in Europe as well as Canada have been tense since Trump came to office pledging to impose tariffs over what he called unfair trade balances.

There have also been fears that the US will pull its forces out of Europe, especially after comments by high-level figures in the Trump administration.

But on Thursday, ahead of the meeting, NATO chief Mark Rutte sought to assuage these fears, saying there would be no "sudden" withdrawal of US forces from Europe.

Rutte and Rubio seek to calm concerns ahead of NATO meeting

"There are no plans for them to all of a sudden draw down their presence here in Europe," Rutte, the former Dutch prime minister, said.

He went on to say that the US had to "attend to more theaters than one."

Rutte sidestepped a question about what he thought the reaction would be to US Secretary of State Marco Rubio, who is also attending the summit.

"The focus here of all 32 [NATO members] is how to defend NATO territory against the Russians, our long-term threat, which will be there even after, I hope there will be a deal on Ukraine," Rutte told journalists.

Asked whether he thought the US was still a trustworthy ally in NATO, Rutte said "Absolutely, they are."

For his part, Rubio said that NATO members should increase their defense spending to 5% of GDP ahead of the talks.

"We do want to leave here with an understanding that we are on a pathway, a realistic pathway, to every single one of the members committed and fulfilling a promise to reach up to 5% of spending. That includes the US," he said. 

In an attempt to show Washington's continued commitment to the alliance, Rubio said the US was "as active as it has ever been."

Edited by: Wesley Dockery