OSAN AIR BASE, SOUTH KOREA – Four U.S. F-22 stealth fighters flew low over South Korea on Wednesday in a clear show of force against North Korea, a day after South Korea’s president warned of the North’s collapse amid a festering standoff over its nuclear and missile ambitions.
The high-tech planes capable of sneaking past radar undetected were seen by an Associated Press photographer before they landed at Osan Air Base near Seoul. They were escorted by other U.S. and South Korean fighter jets.
Pyongyang will likely view the arrival of the planes flown from a U.S. base in Japan as a threat as they are an apparent display of U.S. airpower aimed at showing what the United States can do to defend its ally South Korea from potential aggression from North Korea.
“The F-22 ‘Raptor’ is the most capable air superiority fighter in the world, and it represents one of many capabilities available for the defense of this great nation,” Lt. Gen. Terrence J. O’Shaughnessy, deputy commander of the U.S. military command in South Korea, said in a statement.
“The U.S. maintains an ironclad commitment” to the defense of South Korea, he said.
The U.S. military would not say how long the F-22s will be deployed in South Korea.
The United States often sends powerful warplanes to South Korea in times of tension with North Korea. Last month it sent a nuclear-capable B-52 bomber to South Korea after North Korea defiantly conducted its fourth nuclear test.
The international standoff over North Korea deepened earlier this month when Pyongyang ignored repeated warnings by regional powers and fired a long-range rocket carrying what it calls an Earth observation satellite. Washington, Seoul and others consider the launch a prohibited test of missile technology.
Foreign analysts say the North’s rocket launch and nuclear test put the country further along it its quest for a nuclear-armed missile that could reach the U.S. mainland.
On Tuesday, a U.S. institute monitoring North Korea’s nuclear site said Pyongyang has made it even harder for intelligence authorities to detect its preparations to carry out a tests and could now conduct its fifth atomic test “with little or no warning.”
The U.S.-Korea Institute of Johns Hopkins University in Washington said on its 38 North website that the fourth and latest test by North Korea on Jan. 6 indicated that Pyongyang “appears to have altered its past test-preparation practices” and that such practices can no longer be detected simply by analyzing satellite imagery.
North Korea said last month it successfully conducted its first hydrogen bomb test, in defiance of repeated international warnings. Many countries are skeptical of North Korea’s claim that it detonated a hydrogen bomb.
The institute released commercial satellite images dated Feb. 1 and Feb. 7 showing the Punggye-ri nuclear test site in North Hamgyong province.
The institute said the images show “unidentified objects in various locations” near the test tunnel, which could be a survey team making an assessment of the January nuclear test, preparing for another test, or sealing the tunnel to prevent radiation leakage.
“While detecting nuclear test preparations is, under the best of circumstances, an inexact art, in the North Korean case it may be the result of careful planning to avoid detection by commercial satellites as they pass overhead or by instituting a practice of gradual, low-key preparations that take place over months — activity almost indistinguishable from construction, tunnel excavation and maintenance,” the institute said.
The institute also warned that North Korea “may have tunnels already completed and ready for a test should it decide to move forward.”
South Korea’s president on Tuesday warned North Korea faces collapse if it doesn’t abandon its nuclear bomb program, an unusually strong broadside that is certain to infuriate Pyongyang.
In a speech at parliament, President Park Geun-hye said South Korea will take unspecified “stronger and more effective” measures to make North Korea realize its nuclear ambitions will result only in accelerating its “regime collapse.”
Park made the speech while defending her government’s decision to shut down a jointly run factory park in North Korea in response to the North’s rocket launch. Pyongyang retaliated by expelling all the South Koreans there, put its military in charge of the area and cut off key communication hotlines between the Koreas.
It is unusual for a top South Korean official to publicly touch on such a government collapse because of worries about how sensitive North Korea is to talk of its authoritarian government losing power. Pyongyang has long accused Washington and Seoul agitating for its collapse.
After the rocket launch, Seoul announced that talks would begin with Washington on deploying a sophisticated U.S. missile defense system in South Korea and that the allies’ annual military drills in the spring will be the biggest ever.
The deployment of the Terminal High-Altitude Area Defense, or THAAD, is opposed by North Korea, China and Russia. Opponents say the system could help U.S. radar spot missiles in other countries.
Pyongyang has also called regular U.S.-South Korea military exercises a rehearsal for a northward invasion. The allies say their drills are defensive in nature.