Kohl said he would like the fight between Tyson and Klitschko, the German- based World Boxing Organisation heavyweight champion, to be staged in Hamburg's football stadium.
The fight, that was originally scheduled for January, would be Tyson's first since his bout against Orlin Norris in Las Vegas in October was ruled a no contest. Norris injured his right knee and could not continue after falling to the canvas when Tyson punched him after the bell at the end of the first round.
The Norris bout marked Tyson's return to the ring after a nine-month absence during which he spent almost four months in jail for assaulting two motorists after a traffic accident.
n Salford's Steve Foster will challenge South Africa's Mpush Makambi for his International Boxing Organisation middleweight title in Manchester on Saturday night. Makambi will be making his fourth successive trip to Britain, having twice stopped Adrian Dodson last year and recorded a second- round knock-out win over Ensley Bingham in October.