The handover would grant South Korea full control of its military in the event of a conflict. But the transfer might be delayed yet again.
As part of his four-country tour of Asia, Obama will visit the Philippines Monday. He's expected to highlight the importance of security cooperation and the Philippines' strategic role in the region.
North Korea backed off its threat to block reunions of families split by the Korean War, after Secretary of State Kerry refused to budge on planned military exercises with South Korea.
Defense Secretary Hagel's comments about the North's chemical arsenal come amid new concerns over the sophistication of North Korea's nuclear weapons program.
When North Korea shut down the industrial park it jointly maintained with South Korea in April, it ratcheted tensions to a new high.
Russians, Chinese, Brazilians, and others are traveling abroad as never before as the world's growing middle classes get itchy feet.
On the 63rd anniversary of the Korean War that divided the peninsula, hackers hit systems in both North and South Korea.
North Korea's refusal to take South Korea's phone calls has dashed hopes for proposed peace talks.