"The government and those in the telecommunication industry including the three mobile carriers and smartphone manufacturers agreed that the launch of commercial 5G services should not be delayed any longer and made a decision to launch them in a blitz on April 3", Yu said.
5G will allow users to download movies in less than a second.
The company claimed that with using its self-developed "Total In-building Solution", it could provide in-building data rates that were four times faster than its competitors by utilising the four antennas of a smartphone.
For general customers, the services will be available from Friday - the previous launch date - when Samsung Electronics rolls out the Galaxy S10 5G, the world's first available smartphone using the technology.
According to market speculations, South Korea recognized itself as the first nation to debut 5G, but US mobile firms did not agree to this, claiming that they had rolled out 5G services in limited regions as early as previous year.
Irene Kim, the spokeswoman for SK Telecom, stated that the company conducted internal meetings and chose to introduce the 5G service prior to the planned date as the customers and networks were ready.
"SK Telecom today announced that it has activated 5G services for six celebrities representing Korea as of 11 p.m. April 3, 2019", the country's biggest mobile operator said in a news release Thursday.
In Japan, 5G is expected to become available in some parts of the country in the summer at the earliest.
South Korea is all over the news media outlets from the past couple of days and now in yet another remarkable feat, the nation has witnessed the launch of world's first 5G phone. Park Tae-wan, a ministry official, said a "world's first" reference could possibly help the mobile industry market's know-how.
The implications of the new technology have pitted Washington against Beijing - whose firms dominate 5G technology - in an increasingly bitter standoff.
The global telecom industry is now debating on how many subscribers will buy 5G from Verizon that will be available on Motorola's Z3 and a Moto Mod.
But according to Yonhap, the South Korean launches came two hours earlier, at 11pm (10pm Singapore time) on Wednesday.
The S10 5G's screen is great for videos and games and the phone packs readily available 5G networks.
South Korea comes next, with its companies holding 2,051 patents, while USA firms have 1,368 together.
LG Electronics plans to introduce its own 5G smartphone later this month. SK Telecom said it will be offering Galaxy S10 5G smartphone in instalments over 4-years.