Secretary of Homeland Security John Kelly said Friday that North Korea poses a cyber-threat to the United States but a military strike from the nuclear power is unlikely amid escalating tensions between the two nations.

“In the case of North Korea, you know, a kinetic threat (missile attack) against the United States right now I don’t think is likely, but certainly a cyber-threat,” Kelly told NBC News’ Chuck Todd.

“We would raise various threat levels in the event that something happened and we felt as though that there was a possible threat,” he added. “You always want to caution on the side of — come down on the side of caution.”

The full interview with Kelly will air on NBC News’ “Meet The Press” on Sunday.

Tensions between the U.S. and North Korea are near a boiling point over the communist nation’s nuclear program.

Leaders in Pyongyang have announced a “big event” is coming soon, which U.S. officials believe could be a sixth nuclear test.

Senior U.S. military officials told NBC News they were prepared to launch a preemptive strike with conventional weapons if they learned North Korea would carry out a nuclear weapons test. The U.S. positioned two destroyers in the region, with one 300 miles from the nuclear test site.

North Korean leaders this week declared they would “hit the U.S. first” with a nuclear weapon if they felt threatened. Officials promised a “merciless retaliatory strike” against the U.S. if signs pointed to American military action.

Despite its nuclear capabilities, military officials say North Korea does not have the technology to strike the U.S. with a weapon of mass destruction. They do, however, threaten U.S. allies like South Korea.