Earlier this month, North Korea's Foreign Ministry warned it could bring back its policy of bolstering its nuclear arsenal if it doesn't receive sanctions relief.
Joseph Yun, former USA special representative for North Korea policy at the State Department, said he supported the idea of Washington adjusting its message to say "we're willing to discuss certain [sanction] exemptions" instead of continuing to insist on providing no sanctions relief to the North without "final and fully verified denuclearisation".
"With Pyongyang testing what appears to some sort of new weapon as well as voicing its anger in state media over and over that negotiations with Washington are not where they want them to be, we should continue to watch the Korean Peninsula very carefully", Kazianis advised.
The North Korean authorities have made a decision to expel a U.S. citizen who was detained in October for illegally entering the country, South Korean Yonhap news agency reported on Friday. "They are trying to send that signal".
"The United States appreciates the cooperation of the Democratic People's Republic of Korea and the embassy of Sweden in facilitating the release of an American citizen", Secretary of State Mike Pompeo released in a statement.
The exact cause of his death remains unknown but a recent USA media report claimed there was new evidence that he was beaten by the regime.
United States authorities have not yet commented on the report.
Despite the testing, the State Department said in a statement that the U.S. remains "confident that the promises made by President Trump and Chairman Kim will be fulfilled".
"We remain confident that the promises made by President Trump and Chairman Kim will be fulfilled", a spokesman said in a statement.
Entidades árabes en la Argentina denuncian persecución hacia la comunidad islámica — Hezbollah
En su domicilio se secuestró una docena de armas, que sus familiares dijeron hoy, en declaraciones a la prensa, que fueron herencia de un abuelo.
"We are talking with the North Koreans about implementing all of those commitments", it continued.
Display of capabilities: North Korean leader Kim Jong-un. Trump subsequently said he expected a second meeting with Kim to occur early next year.
It is rare for North Korea to release an American detainee so swiftly and it comes amid stalled negotiations over Pyongyang's nuclear programme.
Experts say North Korea has been growing increasingly frustrated with the United States over Washington's insistence that sanctions would be lifted only at the end of a long process of denuclearisation.
Currently, there are no known U.S. detainees held by the rigid communist state.
The US citizen, identified as Bruce Byron Lowrance, has been detained in North Korea since he was caught illegally entering North Korea via the border with China last month, according to the Korean Central News Agency.
"While being questioned, he said he had illegally entered the country under the command of the US Central Intelligence Agency", KCNA said.
North Korea did not specify the type of device involved, but South Korean media said it was likely to be new long-range artillery developed under Kim's father and predecessor Kim Jong Il. He provided no other details. "The safety and well-being of Americans remains one of the highest priorities of the Trump Administration".
The North's decision matches its general push for engagement and diplomacy with the United States this year after a string of weapons tests in 2017, and a furious USA response, had some fearing war on the Korean Peninsula.