PUBLISHED: 04:50, Sun, Nov 1, 2020 | UPDATED: 04:50, Sun, Nov 1, 2020
The claim was made by Anthony Gardner, a former American ambassador to the EU, during an address in Germany. During his speech he also described Brexit as “the biggest own-goal that I’ve seen in my lifetime”.
Mr Gardner has been tipped as a potential US ambassador to Britain if Mr Biden is elected president.
Donald Trump by contrast has repeatedly praised Brexit and described Boris Johnson as his “friend”.
However the UK has yet to sign a new trade deal with the US.
On Tuesday Mr Biden made an address at Berlin’s ESMT business school.
Anthony Gardner argued Joe Biden will make a "declaration of support for European integration" (Image: GETTY)
Joe Biden speaking at a rally on Saturday (Image: GETTY)
According to the Sunday Telegraph he said: “If Biden is elected I believe quickly, perhaps first day, [there will be a] declaration of support for the European Union, declaration of support for European integration, declaration of support in favour of NATO, the lynchpin of transatlantic alliance, which has been weakened because of this administration's policies.”
Mr Trump, who ahead of the 2016 presidential election described himself as “Mr Brexit”, clashed repeatedly with Brussels on trade.
During a CBS interview in 2018 he claimed “nobody treats us much worse than