The White House said it took a new warning from North Korea that it was in a state of war with South Korea seriously, but said Pyongyang’s threats were following a familiar pattern.

North Korea earlier delivered the latest in a string of dire threats that have drawn a tough response from Seoul and Washington, and sparked international concern that tensions on the peninsula could get out of control.

Pyongyang said it had formally entered a “state of war” with South Korea and warned that any provocation would swiftly escalate into a nuclear conflict.

While seeking to show appropriate concern at Pyongyang’s latest statement, Washington also sought to place the new North Korean threat into the context of a string of rhetoric from Kim Jong-Un’s regime.

Earlier, deputy White House spokesman Josh Earnest told reporters on Air Force One that Pyongyang was purely to blame for escalating tensions.