Vietnamese President Tran Duc Luong is to visit South Korea, following a visit to Hanoi by DPRK's second in command, Kim Yong Nam.
Vietnamese foreign ministry spokeswoman Phan Thuy Thanh says the dates for the two visits are still being worked out with Seoul and Pyongyang.
Mr Luong told visiting South Korean journalists he will probably travel to Seoul in late August, and diplomatic sources told the AFP newsagency that Kim Yong Nam, will visit Hanoi from July 11 to 14.
Hanoi has developed close economic relations with Seoul since they opened diplomatic ties in 1992, despite South Korea's participation in the Vietnam War alongside US troops.