The US is slated to fly bombers over South Korea after the North's latest nuke test
While the official declined to name the bomber's type or the fleet's size, the flight will take place from a US base in Guam on Tuesday.
South Korea's Yonhap News Agency reported that bad weather had delayed a planned US military B-1B bomber flight to the Korean peninsula that was originally slated for Monday.
On Monday, South Korea's Defense Ministry said the rogue regime is ready to conduct an additional nuclear test at any time.
"Assessment by South Korean and US intelligence is that the North is always ready for an additional nuclear test in the Punggye-ri area," the site of the North's five nuclear explosions, South Korean Defense Ministry spokesman Moon Sang-gyun told a news briefing.
Meanwhile, the United Nations Security Council denounced the latest defiant test from the Hermit Kingdom and said it would begin work on a resolution.
Reuters contributed to this report.