The Taliban insurgents began freeing the Koreans after striking a deal with Seoul and Indonesian negotiators.
"We anticipate that the remaining seven will be released this afternoon," presidential spokesman Chon Ho-seon told a news briefing. "We are working to bring them back into the arms of their families. It's difficult to predict, but it may be as early as this weekend."
The 19 are likely to undergo medical checks in Afghanistan and then fly together on a commercial flight to South Korea.
The South Korean government won praise at home for its part in securing the release, but critics said Seoul may have set a dangerous precedent in negotiating directly with the Taliban.
The Chosun Ilbo, South Korea's biggest daily and one of the leading critics of the President Roh Moo-hyun government, said in an editorial that the administration should be commended for resolving the situation while minimising losses.
It cautioned, however: "For the first time ever, we had to negotiate directly with terrorist abductors. We cannot deny the fact that this precedent could possibly act as a burden on Korea's international image in the future".
Other leading newspapers took a similar editorial line.
WARM WELCOME OR COLD SHOULDER
South Korea's presidential Blue House said that under the deal it struck with the Taliban, it has to withdraw its small contingent of non-combat troops in the country within the year and stop its nationals from doing missionary work in Afghanistan.
However, South Korea had already decided before the crisis to pull its 200 engineers and medical staff out of Afghanistan by the end of 2007. Since the hostages were taken it has banned its nationals from travelling there.
Spokesman Chon has said there was nothing more to the deal than the announced conditions but was evasive in responding to questions at a briefing on Wednesday on whether a ransom was paid, saying only South Korea had done what was needed.
Internet discussion boards in South Korea were filled with messages welcoming the release, but there was also criticism of the suburban Seoul church for making an ill-advised mission to Afghanistan and putting the government in a bind.
Prior to the kidnapping, South Korean had warned its citizens not to travel to Afghanistan and blocked many of its growing legion of evangelical Christians from going there due to safety concerns.
Saemmul Church is in talks with the government over who will pick up the tab for the release. The church will likely pay for the former hostages' return air tickets and cover their medical costs, officials said.
In all, the insurgents seized 23 Koreans on July 19 from a bus in Ghazni province and initially demanded the release of Taliban members held prisoner by the Afghan government.
They killed two hostages, and then released another two earlier in what it said was a goodwill gesture.
