It should have happened years ago, "Trump said from the White House". The president also cited Otto Warmbier, an American student who died in June after being imprisoned in North Korea for 17 months, during Monday's announcement.
Mr Trump visited South Korea earlier this month as part of a 12-day trip to Asia, where he addressed the South Korean National Assembly and issued a warning to the North.
President Donald Trump has announced the United States is putting North Korea's "murderous regime" on America's terrorism blacklist.
George W. Bush originally designated North Korea as a terrorism sponsor, but removed Pyongyang in 2008 in an effort to broker a nuclear deal. It has fired two missiles over Japan and on September 3 fired its sixth and largest nuclear test.
"This designation will impose further sanctions and penalties on North Korea. and supports our maximum pressure campaign to isolate the murderous regime", Trump said. "Putting them back on accomplishes nothing", Lt. Col. Eric C. Anderson, a retired U.S. Air Force Intelligence Officer who spent most of his career focusing on North Korea, told Newsweek".
"In addition to threatening the world by nuclear devastation, North Korea has repeatedly supported acts of worldwide terrorism, including assassinations on foreign soil", Mr Trump said as he announced the designation at a Cabinet meeting at the White House.
Some members of Congress had been pushing for years for North Korea to be put back on the list, but others questioned whether the reclusive regime met the criteria of actively sponsoring worldwide terrorism.
Putting North Korea back on the USA list of state sponsors of terror ups the ante in Trump and Kim Jong-un's public battle, which has sometimes veered toward the personal. With Iran, Sudan, and Syria also being on the list administered by the State Department, exactly what does being a state sponsor of terror mean?
Neither Mr Trump nor the State Department specified which acts of terrorism and assassination the North had supported.
Evans Revere, a former senior State Department official, said North Korea is already livid with Mr Trump and is likely to react "quickly and emotionally".
Kim's government insists it will defy global sanctions to develop a capability it believes is essential to defending itself from the threat of United States and South Korean invasion.