Joint Chiefs of Staff Chairman Gen. Lee Sun-jin on Monday warned that North Korea could stage an additional provocation and urged solid joint defense readiness with the U.S. in the aftermath of the communist state’s fourth nuclear test last week.

Lee visited the Osan air base in Gyeonggi Province with U.S. Forces Korea commander Gen. Curtis Scaparrotti who also called for the personnel there to maintain “top-level readiness with a long-term view,” according to military officials here. 

Their trip to the base, which houses South Korea’s Air Force Operations Command and the U.S. Seventh Air Force Command, came a day after Washington sent a nuclear-capable B-52 strategic bomber over the peninsula, escorted by two South Korean F-15K fighters and two U.S. F-16 fighters, in a display of force against Pyongyang.

“The North Korean military is very likely to commit an additional surprise provocation following the hydrogen bomb test to tackle the current situation,” the JCS quoted him in a statement as saying during the inspection, after a briefing by Air Force Operations Commander Lt. Gen. Lee Wang-keun.

“Our military should consolidate all its capabilities to uphold firmer military readiness posture so as to deter the North’s further provocations and sustain peace and stability on the peninsula.”

Scaparrotti, for his part, also instructed the U.S. Air Force here to stay ready to respond to any possible event with “strong air power” and “the best team.”

During the visit, the two commanders also looked around the Korea Air and Space Operation Center and Theater Missile Operations cell, the JCS noted.

In its first reaction, Pyongyang’s mouthpiece on Monday condemned the B-52’s flight over the Osan base, accusing Seoul and Washington of “pushing the situation to the edge of war.”

After the bomber’s deployment, the allies are exploring additional military steps, while seeking to enforce more crippling international sanctions.

They are believed to be considering advancing their regular joint Key Resolve and Foal Eagle exercises during which Washington would bring in its nuclear-powered aircraft carrier USS Ronald Reagan, a nuclear-powered submarine, F-22 Raptor stealth fighter and/or B-2 stealth bomber.

“South Korea and the U.S. are engaged in close consultations over North Korea’s fourth nuclear experiment. A dispatch of other strategic assets over the peninsula than the B-52 is on the agenda for our ongoing discussions, so we will make an announcement when a decision is made,” Seoul’s Defense Ministry spokesman Kim Min-seok told a regular news briefing.

By Shin Hyon-hee (heeshin@heraldcorp.com)