Donald Trump declares 'murderous' North Korea a state sponsor of terrorism

President Donald Trump declared North Korea a state sponsor of terror and promised new sanctions at the "highest level".

Mr Trump cited Pyongyang's nuclear ambitions and assassinations carried out on foreign soil for the decision.

Additional sanctions were expected to be announced by the US Treasury on Tuesday.

US officials highlighted the killing of North Korean leader Kim Jong-un's estranged half brother Kim Jong-nam at Kuala Lumpur airport in February as an assassination on foreign soil. He was sprayed with a nerve agent.

They also said the death of US student Otto Warmbier, who died of injuries suffered in North Korean custody, constituted terrorism.

Mr Trump, speaking at the White House, said: "In addition to threatening the world by nuclear devastation North Korea has repeatedly supported acts of international terrorism including assassinations on foreign soil. North Korea must end its unlawful nuclear and ballistic missile development.

"This should have happened a long time ago should have happened years ago. As we take this action today, our thoughts turn to Otto Warmbier and others affected by North Korean oppression."

The decision came a week after Mr Trump returned from a 12-day trip to Asia where he discussed how to contain North Korea's nuclear programme.

Some officials at the US State department had opposed the decision to designate it a state sponsor of terror, which requires evidence that a state has "repeatedly provided support for acts of international terrorism".

Rex Tillerson, the US Secretary of State, said: "We still hope for diplomacy." But he said there was "no magic wand or silver bullet that's going to bring North Korea to the table".

He added: "This is to hold North Korea accountable. This is all part of continuing to turn the pressure up."

Mr Tillerson said the message to Mr Kim was "this is only going to get worse until you're ready to come and talk". He said there was already evidence of fuel shortages in North Korea due to sanctions, with some petrol stations appearing to be out of supplies.

North Korea was last on the US list in 2008 but was removed then in a bid to salvage a deal to halt its nuclear development.

Since then its nuclear and missile programmes have advanced markedly, and it became capable of reaching US territories earlier this year.

Iran, Sudan and Syria are also designated as state sponsors of terror by the US.

Experts said with North Korea already under existing US and United Nations sanctions being added to the list of state sponsors of terror would not have much immediate economic impact on the rogue nation.