North Korea delivered a fresh round of rhetoric Thursday with claims it had “powerful striking means” on standby for a missile launch, while Seoul and Washington speculated that the country is preparing to test a medium-range missile during upcoming national celebrations.

South Korea and the United States were on high alert for a North Korean missile launch on Thursday as the hermit kingdom turned its attention to celebrating its ruling Kim dynasty and appeared to tone down rhetoric of impending war.

South Korean and U.S. forces raised their alert status to “vital threat” Wednesday before an expected North Korean missile test, with tensions wound tight during a five-day buildup to a key anniversary.

Some Chinese tour operators have halted travel to North Korea at the behest of local authorities and because of rising safety concerns as Pyongyang whips up war rhetoric following weeks of tension on the Korean peninsula.

A former North Korean spy who bombed a South Korean airliner said Wednesday that the North's leader Kim Jong Un is struggling to control his military and using war talk to shore up support.

Japan has deployed missile batteries in its heaving capital to defend the 30 million people who live in the Greater Tokyo area from any North Korean attack.

Officials in the Japanese city of Yokohama were left red-faced on Wednesday after mistakenly announcing the launch of a North Korean missile to 40,000 followers on Twitter.

North Korea was responsible for a cyberattack that shut down tens of thousands of computers and servers at South Korean broadcasters and banks last month, officials in Seoul said Wednesday, noting that an initial investigation pointed to a military-run spy agency as the culprit.

North Korea intensified threats of an imminent conflict against the United States and the South on Tuesday, warning foreigners to evacuate South Korea to avoid being dragged into “thermonuclear war.”

With tensions on the Korean Peninsula soaring to include threats of nuclear war, frustration is mounting at what U.S. policy experts see as the failure of all efforts to rein in North Korea.