The US has again flown nuclear-capable bombers over the Korean peninsula in a show of force against North Korea shortly after Pyongyang tested a rocket engine. This is the second time Washington is flying the sophisticated supersonic B-1B bombers since the North carried out its fifth nuclear test on 9 September.

On Wednesday (21 September), the US forces said a pair of B-1B Lancer strategic bombers cruised over South Korea with one of the jets landing at South Korea's Osan Air Base Pyeongtaek, located about 40 km from Seoul. The state-of-the-art bombers were flanked by other American and fighter jets.

"What we are showing today is just one tool we have to choose from a wide array of options. The alliance grows stronger every day and we remain prepared to defend and to preserve the security of the Korean Peninsula and the region," said Lieutenant General Thomas Bergeson of the US Forces Korea. The US had carried out a similar flight in a show of solidarity with its allies, South Korea and Japan, in the region on 13 September.

The Korean peninsula has been witnessing a flurry of activity with the North not appearing to scale down any of its missile programmes. Days after its nuclear test, the reclusive nation's most powerful as yet, the North tested a new rocket engine under the leader Kim Jong-un's supervision at the Sohae Space Centre.

"The Korean peninsula faces a grave security crisis as a result of North Korea's fifth nuclear experiment along with its continued launching of SLBM and ballistic missiles despite the concerns of the International community," said Lieutenant General Lee Wang-keun, South Korea's Air Force Operations Commander.

"The [Republic of Korea] ROK-US Combined Air Forces, acutely aware of this climacteric situation, maintains a close information sharing and a robust combined operational capability. Should the enemy provoke us once again, the Combined Air Forces will respond and eliminate their will and capability to fight."

Global powers are scrambling to give a fitting response to North Korea's defiant acts but so far there has been no consensus on the issue. The US and China, North Korea's key ally and major trading partner, are inching towards ironing out their differences in order to send a strong message to Pyongyang.