President Barack Obama said the U.S. stands "shoulder to shoulder" with its ally South Korea in refusing to accept a nuclearized North Korea.
Addressing a joint news conference alongside South Korean President Park Geun-hye on Friday, Obama said threats by North Korea will get it "nothing except further isolation" from the global community. North Korea has threatened to conduct its fourth nuclear test, possibly while Obama is in the region on a weeklong trip.
Obama also noted that his visit comes at a time of "great sorrow" for South Korea, which is mourning the loss of more than 300 people in a ferry that sank off the country's southwestern coast. The vast majority of the victims were high school students.
"So many were young students with their entire lives ahead of them," Obama said, invoking his two daughters, both close in age to many of the ferry victims. "I can only imagine what the parents are going through at this point, the incredible heartache."