Speaking during a Cabinet meeting, Trump said the designation will impose even greater sanctions on North Korea amid rising nuclear threat tensions with the Asian nation. He said the label is long overdue and is part of the U.S. “maximum pressure campaign” against North Korea.
"In addition to threatening the world by nuclear devastation, North Korea has repeatedly supported acts of international terrorism including assassinations on foreign soil," Trump said.
U.S. officials cited the killing of North Korean leader Kim Jong Un's estranged half-brother in a Malaysian airport in February as an act of terrorism.
North Korea was removed from the list – which includes three other countries – in 2008 in an effort to salvage a deal to halt its nuclear development. However, since then, North Korea has made significant strides in its nuclear program.

What does the designation mean?

In order to end up on the list, countries have to repeatedly prove “support for acts of international terrorism,” according to the Department of State.
Trump promised the designation would impose additional penalties on North Korea.
Sanctions can include: restrictions on foreign assistance from the U.S.; ban on defense exports and sales; control over certain exports of dual use items and other financial restrictions.
Other people and countries could also be sanctioned if they engage in “certain trade with state sponsors,” the State Department said.

Who else is on the list?

Iran, Sudan and Syria are the only three countries currently listed by the State Department as state sponsors of terrorism.
Syria was designated in 1979, Iran in 1984 and Sudan in 1993.

How can a country be taken off the list?

There are two ways a country can be taken off the list of a state sponsor of terror, according to a 2016 State Department report.
In one instance, the president would need to submit a report to Congress which shows “a fundamental change in the leadership and policies of the government of the country concerned,” proof that the country’s government is not supporting international terrorism acts and the government’s assurance “that it will not support” those types of acts in the future.
The president can also submit a report to Congress at least 45 days in advance that shows the country at issue has not supported international terrorism in the last six months as well as has provided assurance that it will not do so in the future.
The Associated Press contributed to this report.