One controversial poisoning, two very different perspectives.
The US has joined the UK in accusing Russia of behind a chemical attack on former Russian spy Sergei Skripal in Salisbury, England.
But Russia, responding to the claims at a meeting of the UN Security Council on Wednesday, said it had nothing to do with the incident.
Nikki Haley, the US' ambassador to the United Nations, said: "The United States believes Russia is responsible for an attack on two people in the United Kingdom using a military-grade nerve agent."
"It is not a weapon that can be manufactured by non-state actors," said Haley's UK counterpart, Jonathan Allen. "It is so dangerous it requires the highest-grade state laboratories and expertise.
"Based on the knowledge Russia has previously produced this agent and combined with Russia's record of conducting state-sponsored assassinations ... the UK government concluded that it was highly-likely that Russia was responsible for this reckless act."
Vasily Nebenzya, Russia's ambassador to the UN, denied Moscow's involvement in the poisoning and demanded material proof from the UK to support its charge.
He said: "We were given an ultimatum and requested in 24 hours to admit that we committed a crime. In other words, confess.
"We do not speak the language of ultimatums. We do not use that language with anyone. And we won't be spoken to in that language either."