SEOUL (Reuters) - South Korea plans to buy an additional 20 F-35A stealth fighter aircraft from the United States, a South Korean newspaper reported on Thursday, less than two months after U.S. President Donald Trump announced Seoul would be purchasing billions of dollars in new military equipment. South Korea s Defence Acquisition Program Administration has  established a process for procuring the 20 additional aircraft, the Joongang Ilbo newspaper reported, citing multiple government sources. In 2014 South Korea formally announced a plan to buy 40 F-35As from American defense contractor Lockheed Martin. 