Britain has urged Malaysia to send any evidence it has that links the assassination of Kim Jong-nam with the deadly VX nerve gas to the United Nations.
Jong-nam, who was Kim Jong-Un's half-brother, is said to have been poisoned with the lethal substance in Kuala Lumpur airport on 13 February.
Matthew Rycroft, Britain's ambassador to the UN, told reporters on Monday (27 February) that a chemical weapon attack of this nature needs to be shared with the organisation for further analysis and confirmation.
"If they have got evidence, they should send it to the OPCW [Organization for the Prohibition of Chemical Weapons] and to the Security Council," Rycroft told journalists.
"Once they have done that, then we can take it forward."
Rycroft added he hoped that any country, "in this case Malaysia, with potential evidence of something as serious as this, makes it available as soon as possible".
Malaysia is a signatory to the Chemical Weapons Convention, which seeks to eliminate the use of the toxic agents.
The OPCW released a statement last Friday (24 February) stating it was "ready" to help Malaysia with investigations into the use of chemical weapons.
"According to media reports, the Malaysian authorities seem to have determined that the nerve agent VX was used in a killing at the airport on 13 February," a spokesman for the OPCW said.
"Any use of chemical weapons is deeply disturbing. OPCW stands ready to provide its expertise and technical assistance, if required, to any State Party to the Chemical Weapons Convention."
The Malaysian mission to the UN did not immediately comment on whether it wished to proceed.
On Sunday, Malaysia's health minister said that Jong-Nam suffered a "very painful death", with the nerve agent severely affecting his heart and lungs.
"From the time of the onset (of the attack) he died within 15 to 20 minutes," Health Minister Subramaniam Sathasivam told reporters.