Over the past few weeks, the Obama administration has applied doses of both, while keeping up diplomatic efforts. President Barack Obama called Chinese President Xi Jinping in mid-March to discuss North Korea.
Military maneuvers in South Korea have served as a reminder of the overwhelming deterrent force the U.S. and its ally maintain. The deployments also have sent a message to Beijing.
But the North's history of unpredictability means no one knows for sure what it will all mean, even if analysts say North Korea is unlikely to initiate any attack on South Korea like the one that started the Korean War in 1950, and is unlikely to target Japan or American interests in the region.
AP Intelligence Writer Kimberly Dozier contributed to this report from Washington.
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