13 May, 2017
Mr Trump has previously said that he would like to solve the North Korea crisis diplomatically, but that a "major, major conflict" is possible.
But former US officials held two days of informal talks in Oslo, Norway, this week with a Pyongyang delegation led by Choe Son Hui, a senior diplomat for North America.
North Korea's permanent mission to the United Nations late on Thursday issued a statement calling the purported plot to kill Kim a "declaration of war".
"Seoul's power is much greater than Pyongyang's, but South Korea's voice can barely be heard on the problems facing the Korean peninsula", the editorial points out. The CIA and the White House declined comment.
The rogue state wants South Korean intelligence service head Lee Byung-ho to face charges over a plot to kill its "supreme leadership".
North Korean state media has been running stories about the plot since last week.
Earlier this month, President Donald Trump said he would meet with North Korean leader Kim Jong Un if the circumstances were right.
Han took that a step further with the extradition statement.
The office said: "We urge the relevant authorities to immediately detect and arrest and hand over to the DPRK the masterminds of the ugly state-sponsored crime, accomplices and their followers".
Restrictions on crude oil exports to North Korea may already be hurting the country. They previously said that claims of their involvement in the alleged plot were "groundless".
In a press statement attached to its letter, North Korea's U.N. mission accused the United States of trying to intimidate countries into fully implementing U.N. sanctions by "openly threatening that they would be faced with "strong measures of sanction" by the U.S". A North Korean parliamentary committee sent a rare letter of protest to the U.S. House of Representatives on Friday, May 12, 2017, over its new package of tougher sanctions.
"These terrorists plotted and planned in detail for the use of biochemical substances including radioactive and poisonous substances as the means of assassination", Vice Minister Han said. As her administration was mired in its corruption scandal, South Korea went ahead with the deployment of the THAAD missile defense system, crossing a red line drawn by China and painting a bleak picture for the outlook for the bilateral relationship. That could slow any attempt at rapprochement with the North's unpredictable leader, Kim Jong Un, at a time of broad global support for sanctions.