Two nuclear-capable US bombers flew over a military base in South Korea early Tuesday in a show of force meant to warn North Korea.
The US and South Korea are taking measures to ward off the North after it tested a nuclear technology for the second time this year. The explosion was North Korea’s fifth and the strongest nuclear experiment to date.
The B-1B Lancer bombers were spotted over the Osan Air Base south of Seoul, Bernama reported Tuesday.
The takeoff was scheduled for Monday but was pushed back due to bad weather, The US Air Forces Korea (USFK) spokesman Christopher Bush said.
South Korea does not have nuclear weapons and relies on the US "nuclear umbrella" as a deterrent to North Korea. The US stations more than 28,000 troops in the South, and tens of thousands more in Japan.
North Korea is aware of the US presence on the peninsula and of what it considers the US nuclear threat. It uses such flyovers and the US military influence in the South in its propaganda as alleged proof of US hostility that it claims as the reason it needs a nuclear bomb program.
Pyongyang's claim to have used "standardized" warheads in the nuclear explosion, making few other nations worry that it is making progress to develop small, sophisticated warheads that can be mounted on missiles that can reach the US mainland.
Nuclear expert Siegfried Hecker, who has regularly visited the North's nuclear facilities, estimates the North may have enough nuclear fuel for about 20 bombs by the end of 2016 and the ability to add about seven new bombs a year.
"Left unchecked, North Korea will likely develop the capability to reach the continental United States with a nuclear tipped missile in a decade or so," Siegfried wrote on the North Korea-focused website 38 North. He said that more troubling was the recent test successes may give North Korea a false sense of confidence.
International diplomatic efforts to rid the North of its bombs have been stalled since the last round of meetings in late 2008. Since then, Pyongyang has increased both its ballistic missile and nuclear bomb development, despite the increasing sanctions.
After the test, the North's nuclear weapons institute said it will take unspecified measures to further boost its nuclear capability. This statement is considered as hint of a possible sixth nuclear test by the US and South Korea.
The South Korean and US intelligence authorities believe North Korea has the ability to detonate another atomic device at any time at one of its tunnels at its main Punggye-ri nuclear test site, where the five previous atomic explosions took place, South Korea's Defense Ministry spokesman Moon Sang Gyun said Monday.