South Korean diplomats and defense officials say that they work behind the scenes to win the soldiers' freedom.
"Unification is a national goal," one senior South Korean diplomat said earlier this year, "and it should stay that way for a good while."
But a South Korean diplomat acknowledged that political factors will also weigh heavily.
American officials have held about a dozen meetings with North Korean diplomats in Beijing.
A South Korean diplomat was released Tuesday after being held hostage for 21 months, officials said today.
North Korean diplomats almost always travel through Moscow on their way to other destinations.
A South Korean diplomat said his country is committed to continuing economic contacts with the north, including aid.
Later, North Korean diplomats indicated that they wanted to continue the talks with the Bush administration.
But American and North Korean diplomats met well into the evening last night.
"The missile crisis doesn't appear to be worsening, but we still have a long way to go before it's over," said a South Korean diplomat.