United States President Donald Trump has extended sanctions on North Korea for a year, citing the "unusual and extraordinary" threat posed by its nuclear weapons program.

Trump on Friday wrote in a notice to Congress that "the existence and risk of proliferation of weapons-usable fissile material on the Korean Peninsula and the actions and policies of the Government of North Korea continue to pose an unusual and extraordinary threat to the national security, foreign policy, and economy of the United States."

The sanctions were renewed under an executive order reauthorizing a "national emergency" originally put in place in 2008.

The extension comes ten days after Trump's historic summit with North Korean leader Kim Jong-un in Singapore.

After the summit, Trump tweeted that "everybody can now feel much safer than the day I took office and there is no longer a nuclear threat from North Korea."

[Photo : KBS News]