The ban was imposed by the Justice Ministry shortly after Oh Dong-woon, the chief of the Corruption Investigation Office for High-ranking Officials (CIO), said it had made a request for the order.
Earlier in the day, Oh Dong-woon said that he had instructed his investigators to request a travel ban for the country's president, Yoon Suk-yeol, amid an investigation into temporarily martial law.
"I have instructed the investigators [to request a travel ban for the president], but this has not yet been implemented," the official told lawmakers, as quoted by the Yonhap news agency.
Earlier, President Yoon apologized for imposing martial law in the country in a public address, saying he would not reimpose it ahead of the impeachment vote in parliament, which he survived.
Yoon declared martial law late on Tuesday, claiming that the opposition was sympathizing with North Korea and plotting a "rebellion." The parliament defied the presidential declaration and voted to lift martial law. The office of the parliamentary speaker, Woo Won-shik, said that the president's declaration was invalid. Yoon withdrew the measure shortly after it took effect.