South Korea coach Huh Jung-moo previously erred on the side of caution by stating his "initial goal" was a place in the last 16 after being drawn with Argentina, Greece and Nigeria in Group B.
"We don't consider...the top 16 as our goal," Lee told South Korea's Yonhap News. "That would be a case of things not turning out well."
The Koreans stormed to the semi-finals in 2002 as co-hosts and their qualifying credentials are second to none in Asia, this their seventh successive World Cup finals.
Their astonishing run to last four under Dutchman Guus Hiddink in 2002 brought the country to a standstill and major cities were transformed into a sea of red as fans flocked in their thousands to watch matches on giant screens.
South Korea have yet to advance beyond the first round on foreign soil but Lee said they could produce another shock at this year's tournament, which begins on June 11.
"We can do better than reaching the top 16," said the 37-year-old keeper, who has made 129 appearances for his country.
"(At) my first World Cup in 1994...I didn't even know what game I was playing in. But young players now have more big-league experience so the pressure should be less."
Captain Park Ji-sung of Manchester United heads a strong contingent of Europe-based players also including Monaco's Park Chu-young and Lee Chung-yong of Bolton Wanderers.
South Korea take on Ecuador in a home warm-up game at the weekend before Huh names his final 23-man squad for South Africa and final send-off game away to fellow qualifiers Japan.
