A meeting between US President Donald Trump and Kim Jong Un is looking less likely than it was when Mr Trump said he would be willing to meet with the North Korean leader, the White House says.
It comes after a 22-year-old University of Virginia student who spent 17 months in a North Korean jail died in a US hospital just days after being released from captivity in a coma.
Otto Warmbier was visiting North Korea as a tourist last year when he was arrested for attempting to steal a propaganda poster. He went on to be sentenced to 15 years hard labour and his family say he slipped into a coma shortly afterwards in March 2016.
Since Mr Warmbier's death Mr Trump has slammed North Korea on Twitter, saying: "The US once again condemns the brutality of the North Korean regime as we mourn its latest victim."
In another tweet the US President said: "While I greatly appreciate the efforts of President Xi & China to help with North Korea, it has not worked out. At least I know China tried!"
Following the incident US citizens could soon be stopped from travelling to the secretive country.
Doctors at the University of Cincinnati Medical Centre who cared for Mr Warmbier said he had suffered extensive brain damage that left him in a state of "unresponsive wakefulness." He had also showed no sign of understanding language or awareness of his surroundings and made "no purposeful movements or behaviours".
The Warmbier family confirmed on Monday that he had died.
"Unfortunately, the awful torturous mistreatment our son received at the hands of the North Koreans ensured that no other outcome was possible beyond the sad one we experienced today," the family said in a statement after Mr Warmbier's death.
The circumstances of his detention in North Korea and what medical treatment he may have received there remained a mystery, but relatives have said his condition suggested that he had been physically abused by his captors.
US Secretary of State Rex Tillerson vowed to hold North Korea to account for Mr Warmbier's death, plus work to released three other "illegally detained" Americans.
Warmbier family chooses not to conduct autopsy
An Ohio coroner will not perform an autopsy on the US student who died after being held prisoner in North Korea for 17 months and will perform an external examination of the body at the family's request.
The Hamilton County Coroner's Office was conferring with doctors at the Cincinnati hospital where Otto Warmbier, 22, died on Monday, before reaching any conclusions about his death, investigator Daryl Zornes said.
Investigators were still reviewing radiological images and awaiting additional medical records requested by the coroner, Zornes told Reuters.
Earlier the coroner's office said it had received Warmbier's body for an autopsy examination and was expecting to release preliminary findings later on Tuesday or on Wednesday.
But plans changed after the coroner's office decided at the family's urging not to conduct an autopsy, instead limiting its examination to an external analysis of Warmbier's remains and review of his records, Zornes said.
There was no immediate word from the family about why relatives opted not to perform an autopsy, which may have shed more light on the cause of the neurological injuries Warmbier suffered in North Korea.
The circumstances of his detention and what medical treatment he received in North Korea remain unknown.