The Organisation for the Prohibition of Chemical Weapons confirmed the UK's findings that Novichok was used to target the former Russian double agent Sergei Skripal and his daughter Yulia in the English city of Salisbury.
While the statement from the OPCW does not specifically name Novichok, it says technical experts "confirm the findings of the United Kingdom relating to the identity of the toxic chemical that was used in Salisbury and severely injured three people."
The UK government says its scientists have identified the agent as a military-grade Novichok nerve agent.
The OPCW, the international chemical weapons watchdog, said its team "notes that the toxic chemical was of high purity. The latter is concluded from the almost complete absence of impurities."
Britain has accused Russia of attempting to murder the Skripals using Novichok. Russia has repeatedly denied involvement in the attack, seeking to blame Britain instead.
The OPCW sent a team of specialists to the UK last month to investigate the March 4 attack.
The experts took samples from several locations as well as biomedical samples from the Skripals and police officer Nick Bailey, who was also exposed to the nerve agent.
UK Foreign Secretary Boris Johnson said the testing was carried out by "four independent, highly reputable laboratories around the world," all of which "returned the same conclusive results."
"There can be no doubt what was used and there remains no alternative explanation about who was responsible -- only Russia has the means, motive and record," Johnson said in a statement.
"In the interest of transparency, and because unlike the Russians we have nothing to hide, we have asked the OPCW to publish the executive summary for all to see and to circulate the full report to all state parties of the OPCW, including Russia.
"We will now work tirelessly with our partners to help stamp out the grotesque use of weapons of this kind and we have called a session of the OPCW Executive Council next Wednesday to discuss next steps. The Kremlin must give answers."
The United Kingdom has called for a UN Security Council meeting to discuss the OPCW report, according to a tweet from the UK mission to the United Nations. The meeting is likely to take place next week, according to the tweet.
In his first public speech as director of the UK surveillance agency GCHQ, Jeremy Fleming described the Salisbury attack as "sobering."
"It demonstrates how reckless Russia is prepared to be," he said. "How little the Kremlin cares for the international rules-based order. How comfortable they are at putting ordinary lives at risk."
Fleming added that the "robust response" from the UK and the international community "shows the Kremlin that illegal acts have consequences."
Russia lost a vote at the OPCW earlier this month to have a joint UK-Russian investigation into the Salisbury attack. Moscow has repeatedly complained that it has been denied information on the UK probe and access to the Skripals, who are Russian citizens.
In a statement Wednesday, Yulia Skripal said she did not need help from Russian diplomats in the UK and cautioned the media that no one else speaks for her or her father, who is still in a British hospital. Yulia was discharged from the hospital on Monday.
The chief executive of the Porton Down defense laboratory in the UK said earlier this month that scientists could not confirm where the nerve agent was made.
The British government insisted that additional material from intelligence sources led it to the conclusion that Russia was behind the attack.