These should be tough times for North-South Korean matchmaking, but Hong Seung-Soo says the search for the right husband or wife out-trumps all other considerations -- even threats of nuclear war.

"None of my clients really care about the threats, or the political situation between the two Koreas. The most pressing issue in their lives is getting married," Hong says.

Korean culture has a long, established tradition of marriage broking, stretching from traditional neighbourhood matchmakers to dedicated internet sites.

Few are involved in the specialised market that Hong's agency caters for.

When the newly-divorced Hong re-entered the Seoul dating scene in 2006, he ended up meeting and -- much to his surprise -- eventually marrying a North Korean defector.

"We met at a date arranged by a mutual friend, and I remember thinking, what if she was a communist spy?" Hong told AFP.

It turned out she wasn't and, seven year later, Hong is not only still happily married but has helped to match around 400 South Korean men with brides from the North.

He started off arranging dates between men he knew and defector friends of his wife, before setting himself up as a professional matchmaker.

Inter-Korean marriage is about as niche as niche markets can get.

Sixty years after the end of the Korean War, the two Koreas remain technically at war and cross-border contact between ordinary people in the South and North is essentially non-existent.

Permanent low-level tensions between the two countries frequently escalate to dangerously high levels.

The current crisis, which grew out of the North's nuclear test in February, has been marked by angry warnings on both sides, with the North's bellicose rhetoric including threats of a pre-emptive nuclear strike.

But Hong's business keeps ticking over regardless.

"No matter what the North says, I just focus on my job, which is finding love for these men and women," he said.

In reality, the marriages Hong helps broker are probably more founded in pragmatism than romance -- on both sides.

Since the end of the Korean War in 1953, some 25,000 North Koreans have escaped home -- most after a deadly famine in the mid-90s -- and settled in the South.

About 70 percent are women: a gender discrepancy attributed to stricter controls on the activities of North Korean men that make it harder for them to flee.

Life in the modern, capitalist, hyper-competitive South can be extremely tough for such women, who generally lack marketable skills and are widely discriminated against.

With assimilation such a challenge, many look to marriage as a way forward.

"I wouldn't recommend marrying another defector if you really want to start a brand new life in the South," said Choi Hae-In, who fled Pyongyang in 2009 and married a South Korean man a year later.

"You can learn things a lot faster and adapt to the new world faster by marrying a southerner," Choi said, adding most of her defector friends had ended up with South Korean husbands.

There is no official data regarding inter-Korean marriages, but the number of couples is estimated at around 1,000. Hong's is one of 10 agencies that specialise in North-South match-ups.

Traditionally, women from the North of the Korean peninsula have been considered more beautiful than those in the South, but the real attraction of defectors for some southern men lies in their lowered expectations.

Rapid economic development has had profound social implications in South Korea where few women now aspire to married life in a rural area, or to a traditional wife's role in the same household as her husband's parents.

The dwindling pool of potential brides led to many men in the countryside "importing" wives from Southeast Asian countries like Vietnam.

Hong admits that many of his clients are men who would be challenged in finding a South Korean wife. Some would be considered too short, while others have low incomes or live far from the city.

Women from the North, Hong said, were more willing to adapt.

"Unlike many overeducated, spoiled South Korean girls who have impossibly high expectations, these women are less calculating, more modest and far better cooks," he said.

Lee Keum-Soon, a researcher at the Korea Institute for National Unification, said Hong's characterisations fitted a stereotype of North Korean women that is widespread in the South.

"There's a common fantasy among South Korean men that women from the North are submissive, docile, and less judgemental about their background," said Lee, who voiced serious doubts about the future of any marriage based on such assumptions.

While acknowledging the difficulties defectors face in assimilating in the South, Lee suggested that the image of the vulnerable Northern woman willing to make any compromise was probably wide of the mark.

Any woman strong enough to escape North Korea, take the risky journey through China and make it to the South would quickly adapt and grow beyond the fantasy role a traditional southern man had envisaged for her, Lee said.