NATO demanded Russia cooperate with an international investigation into the poisoning of Alexei Navalny on Friday, as EU diplomats cast doubt over whether the bloc could impose sanctions on Moscow.
Jens Stoltenberg, the alliance’s secretary general, said the suspected use of Novichok against the Russian opposition leader meant the Kremlin had "serious questions to answer".
"NATO allies agree that Russia now has serious questions, it must answer, the Russian government must fully cooperate with the Organisation for the Prohibition of Chemical Weapons on an impartial international investigation," he said.
Dominic Raab, the Foreign Secretary, has supported calls for an investigation into the “utterly deplorable” poisoning and has not ruled out British sanctions. The White House has suggested the US might impose sanctions if Russia is to blame for the poisoning of Mr Navalny.
On Thursday, Josep Borrell, the EU’s chief diplomat, refused to rule out sanctions against Russia after Angela Merkel accused Moscow of using the chemical weapon to poison Mr Navalany, who was flown to Germany for treatment earlier this week.
But EU diplomats were not convinced that there would be the necessary unanimous support for the punitive measures, which would require the backing of all 27 member states at a Brussels summit.
The 2018 Novichok poisoning of the Skripals in Salisbury resulted in strong condemnation of Moscow and the coordinated expulsion of Russian diplomats but not in EU sanctions.
After Skirpal, and in one of the UK’s last diplomatic efforts as an EU member state, the bloc agreed a mechanism to respond to chemical weapons attacks such as those with Novichok, which can result in sanctions.
But diplomats said it would be even more difficult to establish the facts in the poisoning because it took place on Russian territory.
“At this stage the question is who do you sanction and how can you find out what happened in Russia?”, one diplomat told the Telegraph.
“It is difficult. If forced to make a prediction, I'd say as things stand we are more likely to have statements condemning rather than full sanctions but we are at the early stages of this.”
A second diplomat added, “At this stage we are investigating exactly what happened, it is too early to discuss sanctions in detail until we have more information.”
MEPs called for the bloc to impose sanctions over the poisoning and push for an international investigation.
"We remain extremely sceptical that Russian authorities are fit and willing to investigate the real background of this crime,” the European Parliament lawmakers said in a letter to Mr Borrell and Germany, which holds the rotating presidency of the EU.