“Now that RB Leipzig have given me the chance (to join Bayern), I’m not going to start taking players from them,” the 33-year-old told a press conference.
He said he did not plan to return with a Volkswagen van for players.
“I’m not going to hire a T6 to go to Munich and take one or two good players from Leipzig with me,” he added.
He is sure to be reunited with one of Leipzig’s stars after centre-back Dayot Upamecano’s summer move to Munich was announced in February.
Nagelsmann will succeed Hansi Flick at Bayern, who has asked to leave at the end of the season after a falling out with director of football Hasan Salihamidzic over player recruitment.
Nagelsmann, whose contract in Leipzig ran until 2023, said he had not planned to leave so soon.
“I had requests from other clubs but I refused,” he said, before repeating his “lifelong dream” was to coach Bayern.
Leipzig, second to Bayern in the Bundesliga, agreed to let their young coach leave in return for a “very high transfer fee”, club boss Oliver Mintzlaff said.
Several German media outlets have estimated the fee at between €20 million (24.17m dollars) and €30m, including bonuses, which would make him the most expensive coach in football history.
Although he would not confirm these figures, Mintzlaff suggested that they were accurate.
“We do not deny the rumours that are circulating,” Mintzlaff said.
Nagelsmann said he would be taking his assistants Benjamin Glueck and Timmo Hardung, who followed him from Hoffenheim to Leipzig and concluded his remarks by saying: “anything else will cost another 30 million.”