South Korean commandos rescued a 21-man crew from Somali pirates. The renegade gangs captured more hostages in 2010 than in any other year on record, and 22 incidents have already taken place in 2011.
US envoy Stephen Bosworth and South Korea's chief nuclear negotiator appear to be pressing for greater North-South dialogue before returning to the six-party talks.
South Korea's statement that it intends this year to begin preparations to reunify the Koreas will likely irk China and the North, which could consider it a provocation.
South Korea launched a planned round of multi-day military exercises Wednesday, while rebuffing the North's recent conciliatory gestures.
North Korea sees South Korea's plans to conduct a live-fire artillery drill this weekend as "needlessly provocative," but the US insists it is normal and necessary.