By Lee Suh-yoonThe government's plan to extend visa waiver policies to tourists from Vietnam, the Philippines and Indonesia is raising concerns about a possible influx of undocumented immigrants.The plan ― extending the five-day mainland visa waiver to group tourists from the three Southeast Asian countries whose final destination is Jeju Island ― was unveiled, Thursday, at a national tourism strategy meeting presided over by Prime Minister Lee Nak-yon in Cheongju, North Chungcheong Province, to help bring 20 million tourists to the country in 2020.The government is expected to announce the revised rules within the month.Tourism industry officials welcomed the plan, saying it would increase the number of inbound tourists."Indonesian tourists show high levels of satisfaction on their visits to Korea," Daisy Park, country manager at the Indonesian tourism ministry's Seoul office, told The Korea Times.This year, the number of Indonesian visitors to South Korea through a MICE visa increased by 50 percent, likely due to the easy availability of the MICE visa, according to Park."I think the benefits outweigh the costs in extending the visa waiver program to Indonesian tourists. More human exchanges will lead to more trade and investment between the two countries," she said.Not everyone is optimistic about the changes. The number of undocumented foreign residents in Korea peaked in 2018, partly due to the expansion of visa-free policies during the 2018 PyeongChang Winter Olympics."The government leaves in place institutions and policies that lead to a proliferation in unregistered immigrants, focusing only on crackdowns to manage the numbers," said Seok Won-jeong, a Joint Committee with Migrants in Korea (JCMK) member who criticized immigration policies and the restrictive employment permit system in a Hankyoreh article in May People from Vietnam, the Philippines and Indonesia are among the top eight nationalities found in the undocumented foreign workforce, which numbered 380,081 in September according to the immigration office. Forty-five percent of undocumented workers entered Korea via visa waiver programs.The concerns come after 164 Vietnamese students disappeared from a one-year foreign student program at Incheon National University's Korean Language Institute last week. Immigration officials suspect they vanished to seek illegal employment here.The government's visa waiver plans are attracting negative and even hateful comments online."Are tour agencies supposed to screen potential undocumented workers on their own? The policy will for sure attract more undocumented foreign residents," one read.Korea allows a 90-day visa waiver policy for visitors from Taiwan, Singapore, Malaysia and Thailand. According to a justice ministry press statement in September, Thai nationals who entered the country through the visa waiver policy made up 37 percent of Korea's undocumented migrant population.Design failures in the government-run Employment Permit System, which assigns legal visas for heavy manual work in Korea for up to four years and 10 months, also contribute to the increasing number of undocumented workers. Previous E-9 visa holders account for around 12 percent of the undocumented workforce. Because the system does not allow workers free change of workplace, rights groups say many are forced to go off the grid to escape abusive employers.