US president Donald Trump has declared North Korea a state sponsor of terrorism.
The designation on Monday allows the United States to impose additional sanctions and risks inflaming tensions over Pyongyang's nuclear weapons and missile programs.
The Republican president, who has traded personal insults with North Korean leader Kim Jong Un but has not ruled out talks, said the Treasury Department will announce more sanctions against North Korea on Tuesday.
The designation came a week after Mr Trump returned from a 12-day, five-nation trip to Asia in which he made containing North Korea's nuclear ambitions a centerpiece of his discussions.
"In addition to threatening the world by nuclear devastation, North Korea has repeatedly supported acts of international terrorism, including assassinations on foreign soil," Mr Trump told reporters at the White House.
“This designation will impose further sanctions and penalties on North Korea and related persons and supports our maximum pressure campaign to isolate the murderous regime.
“It should have happened a long time ago,” Mr Trump said.
North Korea is pursuing nuclear weapons and missile programmes in defiance of UN Security Council sanctions and has made no secret of its plans to develop a nuclear-tipped missile capable of hitting the US mainland. It has fired two missiles over Japan.
South Korea’s spy agency said on Monday the North may conduct additional missile tests this year to polish up its long-range missile technology and ramp up the threat against the United States.
Experts say the designation will be largely symbolic, as North Korea is already heavily sanctioned by the United States.
Only three other countries - Iran, Sudan and Syria - have been designated state sponsors of terrorism by the United States.
Some experts, as well as US officials speaking privately, believe North Korea does not meet the criteria for the designation, which requires evidence that a state has “repeatedly provided support for acts of international terrorism.”
Move could backfire
A US intelligence official who follows developments in North Korea expressed concern that the move could backfire, especially given that the basis for the designation is arguable.
The official, speaking on condition of anonymity, said Mr Kim could respond in a number of ways, including renewing missile or nuclear tests in “a very volatile environment.”
The move also could undercut Mr Trump’s efforts to solicit greater Chinese cooperation in pressuring North Korea to halt its nuclear and ballistic missile tests, the official said.
In any case, it will do little to open the way for US dialogue with North Korea, which China and others have been pushing for.
In February, plans for talks in the United States between former US officials and North Korea were scrapped when the State Department denied a visa for a top envoy from Pyongyang after the murder of Mr Kim's half brother, Kim Jong Nam, in Malaysia.
The assassination also derailed “the first meaningful opportunity” for direct contacts between the two governments, a senior State Department official recently said.
North Korea was put on the US terrorism sponsor list for the 1987 bombing of a Korean Air flight that killed all 115 people aboard. But the administration of former president George W Bush, a Republican, removed Pyongyang in 2008 in exchange for progress in denuclearisation talks.
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 international terrorism.
Representative Ed Royce, the Republican chairman of the House of Representatives Foreign Affairs Committee, applauded the decision, saying that the assassination in Malaysia and the government's other actions justified it.
"This designation ... rightly exposes the Kim regime's utter disregard for human life and is an important step in our efforts to apply maximum diplomatic and financial pressure on Kim Jong Un, " Mr Royce said in a statement. - Reuters