EU Commission chief Jean-Claude Juncker is recovering from "painful attack of sciatica" he suffered at the meeting in Brussels, the commission spokesman Margaritis Schinas has said rebuffing "insulting" rumors of drunkenness.
The spokesman Steffen Seibert made the statement in response to questions about Juncker's health, after he was helped by European Union leaders when he lost his footing at an outdoor music event ahead of a gala dinner at the Brussels summit.
Dutch Prime Minister Mark Rutte also stepped in to guide Mr Juncker at the event in Brussels on Wednesday night.
"The president has himself publicly stated that this sciatica affects his ability to walk".
"That was unfortunately the case Wednesday night".
Sciatica is pain and numbness in the backside and legs that can cause difficulties walking. "I think it's been a very effective way of negotiating, but I'm not negotiating, I just want fairness for the United States", he said. He added that Juncker made no secret about his illness and is now on medication and feels better.
Asked whether Mr Juncker had mixed painkillers and alcohol, Mr Schinas replied: "No he didn't - at least I am not aware of this happening". He has said that he will not run for a second term as Commission president but the obvious question now is whether he is he able to complete his term, which ends in autumn 2019.
The spokesman added that Juncker had a "full programme" at North Atlantic Treaty Organisation and the commission on Thursday, and will stick to a "very demanding agenda" next week including a trip to China and Japan.
Juncker also teased Hungary's hardline right-wing Prime Minister Viktor Orbán over his strongman reputation, jokingly greeting him as "dictator".