With just two weeks to go before America votes, even the country’s top diplomat has his head in his hands.

US Secretary of State John Kerry has told an audience of sixth–formers in London that the presidential election campaign has stepped “out of any norm” and is “downright embarrassing”.

He was being hosted in a Q&A by London’s mayor Sadiq Khan at City Hall, broadcast live on Facebook.

Huge honour to welcome the U.S. Secretary of State @JohnKerry to City Hall for a Q&A with young Londoners. #LondonIsOpen pic.twitter.com/sXEsb4plA3

— Sadiq Khan (@SadiqKhan) October 31, 2016

ITV news reports that when asked about how the election has impacted on US relations abroad, Mr Kerry said: “This election has been difficult for our country’s perception abroad. There are moments when it is downright embarrassing.”

He added: “I could never imagine debates that were not focused on real issues.”

Mr Kerry elaborated: “The way it’s made it difficult for me is that when you sit down with some foreign minister in another country, or with the president or prime minister of another country, and you say, ‘Hey, we really want you to move more authoritatively towards democracy’, they look at you … they’re polite, but you can see the question in their head and in their eyes. And in their expressions. It’s hard.”

However he added he wasn’t “down in his cups” about it, saying the United States has amazing resiliency – and predicted the nation would come out stronger from it.

His host Sadiq Khan, who is Muslim, said earlier this year that Mr Trump should come to London to meet moderates who would challenge his “ignorant” views on Islam.

Mr Trump then retaliated by calling him “rude” and “nasty”.

Asked if he would still welcome Mr Trump if he won the election, Mr Khan said: “Well, let’s wait and see what happens in the presidential election. I’d welcome any US president to my great city of London.

And I look forward to Hillary coming here as soon as she’s the president.”

Mr Kerry’s comments at the Q&A come after yet another turbulent week in the election campaign, with the most recent developments focusing again on Hillary Clinton’s email practices. 

The FBI’s announcement that it was reopening an investigation into her private email server has sparked Democratic Party heavyweights to accuse it of a conspiracy against Clinton. 

The White House has since expressed trust in the integrity of FBI director James Comey.

Republican candidate Donald Trump has pounced on the situation at a rally in Michagan, telling supporters Hillary has put the safety of the American people at risk.

He said it was the biggest scandal since Watergate, and “Hillary has brought this on herself”.

– with agencies