Tuesday's announcement came as Matt Pottinger, senior director for Asian affairs at the US National Security Council, vowed joint efforts to curb the North's military ambitions during a visit to Seoul.
Former President Park Geun-hye first approved THAAD past year, and her government and the USA argued it was exclusively for defense against North Korea's growing nuclear and missile threats.
North Korea conducted two nuclear tests past year which are likely to have improved its know-how in making nuclear weapons small enough to fit on long-range missiles.
Anchor: The U.S. Defense Department says it will hold talks with the new South Korean government about the deployment the THAAD antimissile system.
"We now need to apply pressure on North Korea, and Japan and the United States need to coordinate closely so as to apply pressure", Abe told reporters. The allies agreed that dialogue with North Korea could happen under the "right conditions", Yoon said.
The thorny issues involving the deployment of the U.S. Terminal High Altitude Area Defense (THAAD) system in South Korea were also discussed during the meeting, Pottinger said.
"The new order is reflective of President Moon's commitment to recognize the fine dust issue as a national crisis and provide a solution to the biggest health problem now facing the country", Blue House officials said.
"We will prepare the summit as an opportunity to cement personal ties and friendship between the two leaders", Yoon said. "I am fully confident that it's only going to grow stronger between our administrations", Pottinger added.
Moon has said he would be willing to visit the North "in the right circumstances", but also slammed Sunday's launch as a "reckless provocation", saying dialogue would be possible "only if the North changes its attitude". He has shown a willingness to challenge the United States, saying that Seoul should reconsider its deployment of an advanced USA missile defense system to better cope with North Korean threats.
But Washington is Seoul's closest ally and military protector, and the North's rising nuclear and missile tests make close coordination crucial. It would be Korea's first summit meeting with Trump who took office in January amid vacuum in leadership in Seoul following impeachment motion on former president Park Geun-hye.