University of Hawaii students received an "ominous email" on Monday from the school that had a subject line that read: "In the event of a nuclear attack."
The university sent the email to prepare students, faculty and parents about "the unlikely but not impossible threat of a nuclear missile attack that North Korea poses to the islands," according to Hawaii News Now.
The university's email said, "In light of concerns about North Korea missile tests, state and federal agencies are providing information about nuclear threats and what to do in the unlikely event of a nuclear attack and radiation emergency."
The university's email also told residents and visitors to the school to prepare for emergency sirens and to follow instructions.
One of the school's professors, Diane Desierto, tweeted her reaction to the email.
The email comes amid rising tensions between the United States and North Korea. President Donald Trump and North Korean leader Kim Jong Un have engaged in a war of words for weeks.
Most recently, multiple reports suggest North Korean hackers stole information from South Korea that outlines plans for war-time efforts between the South Korea-U.S. coalition and North Korea, according to the BBC.
Trump tweeted this week that diplomacy between North Korea and the U.S. may no longer be an option.