The United States will consider deploying more high-profile military assets on the Korean Peninsula in the event of a fifth North Korean nuclear test, analysts said Wednesday.
South Korea and the U.S. may also include Japan in their regular joint military exercises in line with three-way "defense-related measures" suggested by U.S. Secretary of State for East Asian and Pacific Affairs Danny Russel to deter North Korea's nuclear ambitions, the experts added.
"I don't think Russel meant direct attacks on North Korea, including surgical strikes on nuclear facilities," said Yang Uk, a senior research fellow at the Korea Defense and Security Forum. "It's more likely that Seoul and Washington will scale up their annual military exercises by inviting Japan to join."
In an interview with Reuters, Tuesday, Russel said Washington, Seoul and Tokyo could take "defense-related measures" if Pyongyang carries out another nuclear test following its fourth test on Jan. 6.
"As the threat grows, then our defensive capabilities need to adjust as well," Russel said without elaborating further.
Park Won-gon, an international relations professor at Handong University, speculated that Seoul and Washington may speed up their discussion on setting up the Terminal High Altitude Area Defense (THAAD) system, an advanced U.S. missile shield, on South Korean soil.
"Given that North Korea's fourth nuclear test accelerated talks concerning THAAD, a new nuclear test may lead the two allies to come up with more specific plans to allow American forces stationed here to bring in THAAD," Park said.
He also said Seoul may ask Washington to regularly fly U.S strategic bombers, such as B-2 and B-52 strategic bombers, over the peninsula.
The U.S. Air Force has sent its advanced aircraft in a show of force following North Korea's nuclear tests in the past, including an occasion in January when a B-52 bomber made a low-flight over Osan Air Base after it was dispatched from Guam.
Park added that Seoul and Washington could carry out two annual spring military exercises ― Key Resolve and Foal Eagle ― on a broader scale.
Involving over 300,000 South Korean troops and 15,000 U.S. personnel, this year's computer-simulated Key Resolve and Foal Eagle combat field drills conducted on land, sea and air, have been the largest-ever in terms of scale.
"It's possible the U.S. may bring its nuclear-powered aircraft carriers, such as USS George Washington to both West and East seas during the drills despite any protest from China," said An Chan-il, the head of the World North Korea Research Center.
"We can't rule out possibilities that those U.S. warships will constantly sail near the Northern Limit Line (NLL) in the future," he added, referring to the maritime border between the two Koreas.
The analysts speculated that Japan's Self-Defense Forces (SDF) may send its Ageis destroyers and patrol planes to operate outside South Korean waters and skies in support of Seoul-Washington combined forces.
"The Japanese military will only be invited to join the drills to the extent that its involvement would not stir up historical disputes between Seoul and Tokyo," Park said.
South Korean politicians and civic groups have opposed the SDF entering the peninsula, citing Japan's unrepentant view over its 1910-45 colonial rule over Korea, which involved crimes committed by the Japanese military.
"If it joins the South Korea-U.S. military exercises, Japan's main mission may be inspecting ships suspected of being engaged in trade with North Korea in open waters," Yang said.
In the interview, Russel warned that the impoverished Kim Jong-un regime will face tougher sanctions, including cutting-off the flow of hard currency earned by the country's workers who are forcibly sent abroad, in the event of a fifth nuclear test.
He also said there are diplomatic options that the North could take by "reviving long-dormant negotiations on curbing its nuclear program."
Meanwhile, U.S. Deputy Secretary of State Tony Blinken and First Deputy Director of National Security Cho Tae-yong agreed to keep up pressure on North Korea for it to abandon its nuclear program in a meeting at Cheong Wa Dae, Wednesday.