The former prime minister had previously warned that leaving the European Union would be an “act of economic and political self-harm”.
The ex-Conservative leader said he had honoured his election promise to hold the referendum and was now supportive of Theresa May’s efforts, even after she was forced to defer an MPs’ vote on her Brexit withdrawal plan.
Approached by Sky News while getting into his car, Mr Cameron said: “I don’t regret calling a referendum.
“I made a promise in the election to call a referendum and I called the referendum.
“Obviously I’m very concerned about what’s happening today but I do support the prime minister in her efforts to try and have a close partnership with the European Union.
“That’s the right thing to do and she has my support.”
Just before the 2015 general election Mr Cameron told voters they faced a “simple and inescapable choice – stability and strong government with me, or chaos with Ed Miliband”.
During campaigning on the EU membership issue Mr Cameron said leaving the single market would be “needless and reckless” and that cutting ties with Brussels would “hit our service industries hard”.
After insisting he would stay on whatever the outcome of the vote, he resigned the day after the narrow Leave win on June 24, 2016.
Some MPs have been critical of his decision to leave front-line politics, like Labour’s Barry Sheerman, who recently said Mr Cameron and George Osborne “ran away from their responsibilities”.
A more colourful intervention came from EastEnders actor Danny Dyer, who told Good Evening Britain in June: “How comes he can scuttle off? He called all this on.
“Where is he? He’s in Europe, in Nice, with his trotters up, yeah, where is the geezer? I think he should be held to account for it.”
Mr Cameron is currently writing his memoirs and is now the president of Alzheimer’s Research UK and chairman of youth development programme National Citizen Service (NCS).
He was recently rumoured to be gearing up for a return to politics.