few changes to the pit lane, and the layout a bit in a few corners," he told reporters.
"They have changed the schedule of the circuit so they are not racing on it any more this year because they start to rebuild it."
South Korea is due to switch to an April 27 date but the race has made heavy losses since its debut in 2010, with sparse crowds, and local promoters are seeking to renegotiate their terms with Ecclestone.
Few in Formula One would mourn its passing, despite the country's economic importance.
"We want to improve the current contract with Formula One Management. We are still negotiating with Mr Ecclestone," race promoter Won-Hwa Park told Sky Sports news this week.
He put the chances of the race remaining on the calendar next season as only "50/50" but added that South Korea wanted to keep it if possible.
An official banner at the entry to the circuit on Friday declared: "Thank You Mr Ecclestone for 2013 F1 Korean Grand Prix".