Vietnamese women who married Korean men for the first time outnumbered their counterparts from China last year. In a report published last week, Lee Sang-lim of the Korea Institute for Health and Social Affairs said 7,636 Vietnamese women married Korean men in 2011, slightly outnumbering their 7,549 Chinese counterparts.

Chinese women accounted for most migrant wives over the last decade. They topped the list with 7,023 in 2002, followed by 838 Filipinas and 690 Japanese, compared to 474 Vietnamese women.

The number of Vietnamese brides temporarily declined after several were beaten to death by their Korean husbands in 2007 and the Vietnamese government put the brakes on international marriages.

Vietnamese women caught up to their Chinese counterparts in 2010, when they were tied at 9,623.

Numbers of migrant wives from other Southeast Asian countries like Cambodia and the Philippines are also rising slightly.

Lee said many children born to Vietnamese mothers have already reached school age and will soon outnumber children born to Chinese mothers. He called on the government to come up with medium- and long- term policies to help such children, who typically have trouble adapting to school.

"There's often a big age gap between Vietnamese women and their Korean husbands, so it's likely that many migrant wives will have to support their families in about 20 years' time. We, therefore, need to develop vocational and welfare programs for them," Lee added.