Senator John Kerry, the losing 2004 presidential candidate, on Wednesday issued a formal apology for what he called “a botched joke” that was mistaken as an attack on the intelligence of US troops.

“As a combat veteran, I want to make it clear to anyone in uniform and to their loved ones: my poorly stated joke at a rally was not about, and never intended to refer to any troop. I sincerely regret that my words were misinterpreted… and I personally apologise to any service member, family member, or American who was offended,” he said.