In response to the rocket launch, South Korea decided last Wednesday to stop operations at the Kaesong Industrial Zone, which Seoul saw as a key source of hard currency for Pyongyang to develop nuclear and missile programmes. President Park warns of North Korean collapse if it doesn't abandon its nuclear program.
Escorted by 8 other United States and South Korean fighter jets, the radar-evading aircraft landed at Osan Air Base near Pyeongtaek City, 70 km (45 miles) south of the border with North Korea.
OPLAN 5015 is a renewed contingency plan preparing the allies for preemptive attacks against North Korea in the event that signs of a possible North Korean invasion, into the South are detected.
Following its fourth nuclear test - and its first disputed H-bomb test - on January 6, North Korea launched a rocket on February 7 to carry an Earth observation satellite into orbit. The Pentagon also dispatched a B-25 bomber to Korea shortly after the North's nuclear test last month.
Without elaborating, Park said the North has diverted much of the factory workers' pay to the Pyongyang leadership, which directs its nuclear and missile development.
She also warned against using the increased tension for political purposes, which she said: "would be exactly what the North would want to see". Park said South Korea must not provide few-strings-attached large-scale aid to North Korea "like in the past".
Washington and Seoul are seeking support from China, North Korea's main ally, for tougher sanctions against the regime over its recent activities.
Seemingly mindful of domestic oppositions to the THAAD deployment, Park said that "aiming the tip of a sword back to us and dividing ourselves are something that should not happen", calling for a national unity to tackle security issues.
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. Analysts consider these steps to be provocations and clear signs that North Korean leader Kim Jong-Un is determined to create a missile capable of striking the United States mainland.
Previous deployments of the fighter on the Korean Peninsula reportedly scared late North Korean leader Kim Jong-il into holding up and not making public outings.
Seoul officials said North Korea was able to divert Kaesong payments because the workers were not paid directly.
According to Seoul's unification ministry, about 616 billion won (560 million USA dollars) has been funneled into the DPRK government since the factory park started manufacturing products in December 2004.
The ministry did not detail how it arrived at that conclusion. Washington, Seoul and others consider the launch a prohibited test of missile technology.