In a letter addressed to Kim Jong-un, the NGOs, including Amnesty International and Human Rights Watch, urge him to end abuses committed in detention centers and prisons, documented and reported by the United Nations, and called on him to act on the human rights recommendations by the UN, Efe reported.
"As your government undertakes new efforts to increase its engagement with the rest of the world, we urge you to move rapidly to institute lasting improvements to the dire human rights situation" the country, the letter began.
It was sent to Kim ahead of the highly anticipated summit on June 12 between the North Korean leader and US President Donald Trump in Singapore, which is expected to focus heavily on the denuclearization of the East Asian country.
"North Korea's increased dialogue with other countries is a positive step, but before the world gets too excited they should remember that Kim Jong Un still presides over perhaps the most repressive system in the world," Brad Adams, Asia director at Human Rights Watch, said in a statement.
"If he really wants to end North Korea's international isolation, he should take strong and quick action to show the North Korean people and the world that he is committed to ending decades of rights abuses," Adams added.
"Understandably, human rights are not the primary objective of the summit, the focus of which are denuclearization and security issues," Arnold Fang, East Asia Researcher at Amnesty International said.
The expert said that the human rights "should be raised at any discussion with North Korea" adding that AI and other international organisations had already asked Trump to include the issue in his dialogue with the North, in a letter sent in May.