Experts said that the U.S. seems to accept Seoul's call for the U.S. to offer more powerful and effective extended deterrence as some lawmakers and experts here raised the need for South Korea's nuclear armament.
Calls are also mounting in the South for Seoul to build nuclear weapons of its own to defend itself as nuclear-armed North Korea's missile stand-off with the USA escalates.
"President Moon Jae-In ordered the toughest retaliation measures against North Korea's ICBM level missile and nuclear provocations, mobilizing all diplomatic means to totally isolate North Korea", Chung Eui-Yong, director of the national security office in the South Korean president's office, said on Sunday in a nationally televised press briefing.
"It is believed that the United States is positive toward rotational deployment of F-22 and F-35B jets over Korea as it remains firm in countering North Korea's provocations", a government source said.
Both the leaders have agreed during the conversation that South Korea's military arsenal would have to be strengthen in a bid to equip the nation better, to deal with the constant threat from Kim Jong Un-led North Korea.
Meanwhile, the White House said in a statement, without explicitly mentioning the missile guidelines, that the leaders "agreed to strengthen" their alliance and Seoul's defense capabilities.More news: Alabama-South Korean Trade Endangered
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"President Trump provided his conceptual approval of planned purchases by South Korea of billions of dollars in American military equipment". Another issue discussed by the defense chiefs was increasing the strength of the missiles in South Korea's arsenal.
North Korea sharply raised regional tension this week with the launch of its Hwasong-12 intermediate-range ballistic missile that flew over Japan and landed in the Pacific.
This photo, provided by the presidential office on August 21, 2017, shows President Moon Jae-in speaking during a National Security Council session at the presidential office Cheong Wa Dae in Seoul.
In July however, Pyongyang snubbed Jae-in's invitation for talks.
However, Trump said after the latest missile test that negotiations with Pyongyang were "not the answer".
Yonhap added that the two leaders reaffirmed the need to bring Pyonyang back to the dialogue table by applying maximum sanctions and pressure.