Toure, 30, was suspended after testing positive for a specified substance and is currently awaiting the results of the B sample.
His former manager at Arsenal, Arsene Wenger said that he understand that Toure had taken a weight-loss product by mistake to control his weight, but neither his club, nor the English FA have said what he has tested positive for.
Toure arrived at the Soccerex business forum in Manchester and toured a number of exhibitors stands, pursued by a posse of TV crews, cameramen and reporters.
Asked if he knew when he would hear the results of the B sample, he replied: "no comment" - but asked if he had a message for City fans he said: "I will be back soon - I hope so."
The Ivory Coast international defender and former club captain joined City after seven years at Arsenal in 2009 for around 16 million pounds, one of a number of big-name players to move to Eastlands after the club's takeover by billionaire owners from Abu Dhabi.
Toure, who has played over 80 times for his country, was made captain by former coach Mark Hughes but lost the armband this season after the arrival of manager Roberto Mancini.
His younger brother Yaya joined City from Barcelona last year.
