European Commission President Jean-Claude Juncker was experiencing a sciatic attack when he was seen losing his balance ahead of the North Atlantic Treaty Organisation summit gala dinner, a spokesperson said.
The 63-year-old was seen to be unsteady on his feet at the summit dinner in Brussels on Wednesday evening, and had to be helped away in a wheelchair.
The European Commission president "suffered from a very particularly painful attack of sciatica accompanied by cramps", according to Margaritis Schinas.
Portuguese Prime Minister Antonio Costa said on Thursday that Mr Juncker had complained of back pain. "I think it's been a very effective way of negotiating, but I'm not negotiating, I just want fairness for the United States", Reuters quoted Trump as saying.More news: Phillies Reportedly Increase Offer For Manny Machado
"I think it's more than tasteless that some press tried to make insulting headlines by exploiting president Juncker's pain".
Claims that the former prime minister of Luxembourg enjoys a glass of cognac at breakfast were taken so seriously they were reportedly discussed by European Union heads of state prior to Juncker becoming Commission president.
Mr Juncker was attending a gala at the North Atlantic Treaty Organisation summit in Brussels attended by US President Donald Trump and First Lady Melania Trump.
Asked if Juncker, who is also an admitted smoker, had mixed painkillers and alcohol, Schinas replied: 'No he didn't, at least I am not aware of this happening'.More news: Meghan Markle And Kate Middleton Attend Serena Williams’ Wimbledon Final Match Together
'The president has himself publicly stated that this sciatica affects his ability to walk.
'He is taking medication and feels better'.
European Council President Donald Tusk, left, European Commission President Jean-Claude Juncker, right, and NATO Secretary General Jens Stoltenberg shake hands after the signature of the second EU NATO Joint Declaration, in Brussels on Tuesday, July 10, 2018.
A European Commission spokeswoman said she would not comment on personal health issues.More news: Chelsea complete signing of Jorginho from Napoli on five-year deal
Juncker also teased Hungary's hardline right-wing Prime Minister Viktor Orban over his strongman reputation, jokingly greeting him as "dictator".