North and South Korea sat down to urgent top-level talks, seeking some way out of an escalating crisis that has pushed both their militaries to the brink of an armed conflict.
US Secretary of State John Kerry discussed security issues with top South Korean officials following a new ballistic missile test by North Korea and the reported execution of its defence chief.
Sony said it has won permission to delay the release of its quarterly earnings report, after a cyberattack damaged the computer network at its Hollywood film unit.
North Korea on Saturday called US President Barack Obama a "monkey" for inciting cinemas to screen a comedy featuring a fictional plot to kill its leader.
A fictional plot to kill North Korean leader Kim Jong-Un drew throngs of moviegoers, as it became an unlikely symbol of free speech thanks to hacker threats.
The devastating cyberattack on Sony Pictures could see the Hollywood studio lose hundreds of millions of dollars in revenue and incur massive recovery costs.
A group which claims to have hacked Sony's servers demanded that its movie studio pull a soon-to-be-released comedy depicting a fictional CIA plot to kill North Korea's leader.
Sony Pictures denounced a "brazen" cyberattack it said netted a "large amount" of confidential information, including movies as well as personnel and business files.
North and South Korea have never found dialogue easy, but academics from both sides currently meeting in Pyongyang are trying to steer things in the right direction.