North Korea's leader Kim Jong Un and US President Donald Trump have signed a comprehensive joint document after their summit in Singapore.

US President Donald Trump has described the document as a “very important” one following the conclusion of their first ever summit in Singapore this morning.

The two leaders have discussed the denuclearization of the Korean peninsula in exchange for the lifting of economic sanctions against Pyongyang and efforts to establish diplomatic relations between the two countries.

There were no immediate details on the contents of the document; however, Trump called it "comprehensive", saying that "both sides will be very impressed with the results."

The process of denuclearization would happen "very, very quickly”, Trump added.

Kim has been quoted as saying that the two leaders had "decided to leave the past behind. The world will see a major change."

According to photographs of the text signed by the two sides, Trump has vowed to provide security guarantees to the DPRK, while North Korea commits to “work towards” complete denuclearization of the Korean Peninsula.

The summit took place following Trump's recent decision to withdraw  from the 2015 Iran nuclear deal, a multilateral agreement that promised lifting of sanctions against Iran in exchange of putting limitations on Tehran’s nuclear program.

Iran’s Foreign Ministry Spokesman Bahram Ghasemi on Monday warned North Korean leader not to trust Trump as the US has a history of “quitting treaties and reneging on its commitments.”