The Asian soccer powerhouse will begin their eighth consecutive World Cup finals campaign against Russia, who they lost 2-1 to in November, on June 17, before clashing with Algeria (June 22) and Belgium (June 26).
Hong, a member of the Korean team that reached the last four of the 2002 World Cup on home soil, said he was close to finalising his squad for the prestigious event.
"We have a lot of young and talented players, but they lack international experience," Hong told reporters in Seoul.
"My job is to try to address that in the coming months. Our core players are aged 22 to 25, and we will need older players for the World Cup to give our team some balance."
Former skipper Hong took over the reins last June after Choi Kang-hee stepped down following an uninspiring World Cup qualifying campaign that saw the Koreans grab an automatic berth by the skin of their teeth.
Hong assisted Dutchman Guus Hiddink, who led South Korea to the semi-finals in 2002, at Russian club Anzhi Makhachkala and impressed as coach of the country's Olympic team, winning the bronze medal at the 2012 London Games.
South Korea avoided the traditional powerhouses in their group during the World Cup draw, boosting their optimism for a strong showing in Brazil but Hong was guarded in his outlook.
"It is not that bad of a draw for us, but we have to remember that there's never an easy opponent," the country's most capped player said. "My responsibility is to make sure the players don't loosen up and think we have this one in the bag.
"First and foremost, the goal is to make it out of the group stage. Once you survive that, then you just never know what could happen.
"The focus of our preparation should be on trying to get to the next round."
South Korea will have a training camp later this month in Brazil and will play three friendlies - against Costa Rica, Mexico and the U.S. - as a build-up to the World Cup.
The coach asked the Korean Football Association to organise more friendlies before the World Cup kicks off in June.
"Now as the head coach, I feel a heavier burden of responsibility than I did as a player," Hong added. "To me, the most important thing now is to take my time and prepare for the tournament the best I can.
"I know fans will always ask the question 'why can't we play like we did in 2002?'. Obviously, we have to put up a good result, but I believe our buildup to the World Cup is also significant.
"We have to do the best we can and have no regrets so that we can give our fans a great gift this year."