Late Wednesday evening North Korea announced it would pursue denuclearization by the end of President Trump's first term, or by early 2021. The announcement came via South Korean President Moon Jae-in and his national security advisor Chung Eui-yong, who met with North Korea's Kim Jong Un the day prior.

Kim has reportedly set down a timeline for denuclearization, the first step of which is a meeting summit between himself and the South Korean president in Pyongyang on Sept. 18-20, during which the two have pledged to discuss "practical measures" toward denuclearization.

This included a personal "good faith" message reportedly sent from Kim to President Trump via the South Korean envoy, to which the president has already responded early Thursday morning via Twitter: Kim Jong Un of North Korea proclaims “unwavering faith in President Trump.” Thank you to Chairman Kim. We will get it done together! - Trump stated.

Kim Jong Un of North Korea proclaims “unwavering faith in President Trump.” Thank you to Chairman Kim. We will get it done together! — Donald J. Trump (@realDonaldTrump) September 6, 2018

Kim conveyed the message to President Trump which reportedly reaffirms Kim's trust in Trump regarding prior diplomatic openings, despite the White House canceling a visit to Pyongyang by the secretary of state last month citing lack of progress.

That message, South Korean national security advisor Chung told reporters after his visit, included that, “He particularly emphasized that he has never said anything negative about President Trump.”

Crucially, the developments represent the first time Kim has ever suggested a timeline for dismantling his nuclear weapons program.

Previously the North has offered to give up its nukes only if extensive security guarantees were delivered by Washington, including the removal of all American troops currently stationed on the peninsula and the dismantling of what's been referred to as its 'nuclear umbrella' of deterrence from South Korea and Japan.

The talks included an agreement to to open a liaison office ahead of the Moon-Kim summit to lay the ground work for "practical measures" to be agreed upon.

In his remarks on the planned timeline, Chung further said that Kim showed “frustration over the doubt raised by some parts of the international community about his willingness to denuclearize, and asked us to convey his message to the United States”.

“He said he would appreciate that such good faith is accepted with good faith,” Chung said. “He expressed his strong will to carry out more proactive measures toward denuclearization if action is taken in response to the North’s preemptive steps.”

According to Chung, Kim desires to see the US take equally significant good faith moves such as the North's recent reported dismantling of a nuclear test site as well as a missile engine facility, beyond mere recent pledged of suspending joint military exercises with the South.

While US officials have yet to comment on the developments, and the full contents of Kim's message to Trump have yet to be revealed, North Korean media appeared to confirm the pledge, with the official KCNA news agency saying Kim told the South’s envoys that his “fixed stand” was to transform the Korean peninsula into “a cradle of peace without nuclear weapons, free from nuclear threat”, according to Reuters.

This could constitute the first important breakthrough since Kim and Trump's historic summit in Singamore last June and a fresh sign that Kim is willing to follow through on work toward total denuclearization.