"We believe that it is reasonable (for Lippert) to leave the hospital on Wednesday after having his stitches removed on Monday or Tuesday," Yoo Dae-hyun, a plastic surgeon at Yonsei University's Severance Hospital where the U.S. envoy underwent surgery, told reporters in a briefing.

On Thursday, a knife-wielding assailant slashed Lippert's face and wrist at a breakfast function in central Seoul. The ambassador was taken to a hospital and received more than 80 stitches.

The 55-year-old attacker was immediately arrested. As he was hauled away, he shouted opposition to joint military exercises under way between South Korea and the U.S., in line with North Korean rhetoric.

Yoo said the injured envoy is suffering most from pain in his left arm but added that other side effects have mostly been covered through the surgery.

"The wound is clean and the patient is stable. He has resumed daily activities such as walking and has improved to the point of taking a shower," the doctor said.

Yoon Do-heum, head of the hospital, added that Lippert is recovering quickly and was able to talk well with visitors.

"Regarding the wrist pain, which was one of the most serious problems, Lippert said his pain reached the level of 4, down from a higher level of 7 yesterday," he said. In the scale that measures pain from a scale of 0 to 10, a higher number refers stronger pain. (Yonhap)