The pair also discussed U.S. President Donald Trump's visit to Japan, slated to begin from November 5 among other matters, informed sources said.
"Conventional war with North Korea would be catastrophic both in lost lives and monetary cost...", Reed said.
North Korea's deputy United Nations ambassador Kim In Ryong claimed no country other than north Korea had been the victim of "such an extreme and direct nuclear threat from the US".
Even if North Korea could penetrate US anti-missile defenses, its leaders would have to fear the incalculable damage and destruction from the USA response.
Threats between North Korea and the United States have been escalating over the past year and warnings have been issued back and forth between the two countries on several occasions. U.S. Deputy Secretary of State John Sullivan, after meeting his Japanese counterpart, Shinsuke Sugiyama, told reporters that the focus at the State Department is still on diplomacy to solve the problem and eventually denuclearize the Korean Peninsula.
United States withdrawal from UNESCO 'loss for multilateralism,' says cultural agency's chief
Under the Reagan Administration, the U.S. quit UNESCO in 1984, at the time accusing the agency of a pro- Soviet Union bias. It referred to the holy site only using Muslim names and prompted angry reactions from Israeli politicians.
"The whole mainland of the U.S. is within our firing, and if the USA decides to go to our sacred territory, even an inch, it will not save our severe penalties in any part of the globe", he warned.
Leaflets apparently from North Korea calling Trump a "mad dog" and depicting gruesome images of him have turned up across central Seoul in recent days, adding an unusually personal element to North Korean propaganda.
A member of North Korea's Parliament spoke about the threat of destruction the country faces from the United States. Of course, North Korea has carried out numerous missile tests, and they recently successfully tested a hydrogen bomb warhead.
The European Union has banned sales of crude oil refined petroleum products to North Korea as it further tightened sanctions on the communist country over its nuclear and missile programs.