When asked for more details on Borrell's comments, a spokesperson for the foreign ministry told The Guardian, "We can confirm that's what the minister said, but we won't be making any further comment on the minister's remarks".
According to those accounts, Borrell told his audience that Trump had compared the situation in northern Africa and the Mediterranean to that along the US border with Mexico.
"The border with the Sahara can not be bigger than our border with Mexico", the President is reported to have said. Trump disagreed, according to Borrell's recollection, adding that "the Sahara border can't be bigger than our border with Mexico".
The US-Mexico border is a little under 2,000 miles long.
Prince Harry caught sneaking samosas as he supports Meghan Markle
The 37-year-old said she was "so proud" to live in a city with London's diversity as she delivered her speech without any notes. Based on the way Meghan was looking at Doria before and during the event. we're guessing she'd love to have mama bear close.
An audio file obtained by CNN noted that the minister impersonated Trump's voice as he said: "You need to build a wall around the Sahara", referring to Trump's statement. The desert spreads over parts of 11 countries: Algeria, Chad, Egypt, Eritrea, Libya, Mali, Mauritania, Morocco, Niger, Sudan and Tunisia.
Whether Mr Trump was joking, it is not clear, and Spanish press reports admitted the context of the remarks was unknown.
While the date of Trump's suggestion was not noted, it is believed that it took place during Borrell's trip to the United States in June of this year.
He insisted the U.S. border with Mexico was wider than the Sahara desert.
Migrants have increasingly been looking to Spain after being shunned by Italy's populist government, which has worked to clamp down on refugees, going so far as to shut its ports to migrant rescue ships.