US President Donald Trump on Wednesday once again threatened to cut off trade with Spain as NATO leaders met for their summit in Ankara.

Trump again singled out Spain for particular criticism calling it a "terrible partner in NATO".

"Spain is a wasted cause. We don't want to do any trade business with Spain anymore," he said, asking his Treasury Secretary Scott Bessent to "cut it off".

The Spanish government responded swiftly, taking Trump's threat "calmly and normally", government sources said on Wednesday.

"Our country maintains a magnificent social, cultural and economic relationship with the United States and it is not our intention for that to change," the sources said.