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The European Union's primary Brexit negotiator recently returned to London after a visit to the United States and announced that in addition to Islamist terrorism and Russian President Vladimir Putin, there is a third threat to a united Europe: President Donald Trump.

"Trump spoke very favorably of the fact that also other countries will want to break away from the European Union, and that he hoped for a disintegration of the European Union," said the negotiator, Guy Verhofstadt, according to the German publication DW.

EU members have viewed Trump's choice for EU ambassador, Ted Malloch, with a certain wariness — Malloch is an outspoken and longtime critic of European supernationalism, DW writes. On Friday, when asked by a BBC presenter why he wanted to be the U.S. ambassador to the EU, Malloch replied: "I had in a previous career a diplomatic post where I helped bring down the Soviet Union, so maybe there's another Union that needs a little taming."

But "a disintegration of the Union would be a disaster," Verhofstadt stressed to scholars in London. "Not only for Europe but also, I think, for our allies and for the world."