British Prime Minister Theresa May said the poisoning of a former Russian spy in the southern English city of Salisbury was "part of a pattern of Russian aggression against Europe."
As she arrived for a summit in Brussels on March 22, May also said that she would tell other European Union leaders that they must unite to counter a threat from a Russia that "doesn't respect borders."
Media reports said May would ask the European Council to join London in condemning Russia for allegedly poisoning ex-spy Sergei Skripal and his daughter with a deadly nerve agent.
May's request for a strong statement, while reportedly stopping short of calling for a new round of sanctions against Russia, is expected to meet with resistance from some relatively Moscow-friendly members, media reported, citing senior British officials.
"We're not looking for confrontation or regime change," a senior government official told reporters in London on condition of anonymity. But Britain wants other EU leaders to acknowledge that "Russia is a strategic enemy not a strategic partner."
Britain accuses Russia of using a military-grade nerve agent known as Novichok against the Skripals in the first known offensive use of a nerve toxin in Europe since World War II. Britain has expelled 23 Russian diplomats it says were spies and suspended high-level contacts over the incident."
Russia has repeatedly denied involvement in the poisoning of Sergei Skripal, 66, and his daughter Yulia Skripal, 33. It has ordered the expulsion of 23 British diplomats and the closure of Russian operations of the British Council in Russia, which promotes cultural ties between the two countries, in retaliation for Britain's measures.
Amid a heated war of words between London and Moscow, the Kremlin on March 22 said President Vladimir Putin discussed Britain's "unfriendly and provocative" policy toward Russia with its Security Council.
Meanwhile, the Russian ambassador to Britain, Aleksandr Yakovenko, said his country "can't take British words for granted" and accused British officials of blaming Russia for the poisoning "without any evidence."
On March 21, Moscow held a briefing for foreign envoys during which it suggested that Britain or the United States might have staged the attack. The British ambassador to Moscow skipped the briefing and the British Embassy accused Russia of spreading "lies and disinformation," saying "we received no credible explanation why a nerve agent produced in Russia was used on UK soil."
Arriving in Brussels, May said "Russia staged a brazen and reckless attack" against Britain.
"It's clear that the Russian threat does not respect borders and indeed the incident in Salisbury was a pattern of Russian aggression against Europe and its near neighbors from the Western Balkans to the Middle East," she added.
The prime minister was expected to hold talks on the poisoning with French President Emmanuel Macron and German Chancellor Angela Merkel before briefing all the EU leaders on the British investigation.
EU foreign policy chief Federica Mogherini told journalists that the bloc will express its “strongest possible solidarity” with Britain.
“The strongest political sign we can give is unity, unity, and unity," she added.
But the EU's 28 members can only release a joint statement if there is unanimity, and May will probably need to overcome reluctance from relatively Moscow-friendly EU members Greece and Hungary.
Officials said both countries held back from laying the blame fully on Russia in a special joint statement issued by EU foreign ministers on March 19.
Britain's biggest supporters in Europe hope that Greek Prime Minister Alexis Tsipras will be more open to their arguments than his foreign minister Nikos Kotzias, who diplomats said refused stronger language linking Moscow to the toxin attack in the earlier statement.
One EU diplomat told the Reuters news agency that Britain's backers at the summit want to "go beyond" the wording of the foreign ministers' statement, which said the European Union takes "extremely seriously the United Kingdom government's assessment that it is highly likely that the Russian Federation is responsible" for the poisonings.
According to draft conclusions seen by RFE/RL ahead of the summit, EU leaders are set to ask foreign policy chief Federica Mogherini to look into ways to improve the 28-member bloc's strategic communication, counterintelligence, and cyberdefense in the wake of the attack in Britain.
The bloc's leaders agree that "the European Union must strengthen its resilience to chemical, biological, radiological, and nuclear-related risks, including through closer cooperation between the European Union and its member states as well as NATO," the draft document said.
It added that the EU "should also continue to bolster its capabilities to address hybrid threats, including in the areas of cyberdefense, strategic communication and counterintelligence."
It did not put direct blame on Moscow, repeating some of the wording from the foreign ministers' statement, but opened the door for potential new sanctions by saying member states "will coordinate on the consequences to be drawn in light of the answers provided by the Russian authorities."
The United States, Germany, and France last week backed London's conclusion that Moscow was to blame.
'Solidarity' With U.K.
In a March 21 telephone call between U.S. President Donald Trump and his French counterpart, Emmanuel Macron, the White House said the two "reiterated their solidarity" with Britain and "agreed on the need to take action to hold Russia accountable."
In Paris, Macron said the Salisbury attack "cannot remain without a response," but did not elaborate.
German Chancellor Angela Merkel emphasized Germany's solidarity with Britain in a speech to lawmakers in Berlin on March 21. She said that "a lot of evidence points to Russia and so transparency from Russia is required to quell the suspicion."
Merkel added: "I would be happy if I didn't have to name Russia here, but we can't disregard evidence because we don't want to name Russia."
Also on March 21, European Council President Donald Tusk, who will chair the Brussels summit, appeared to side with Britain, saying: "It is clear we should improve our preparedness for future attacks."
One senior EU diplomat said that, for some governments, the lack of direct proof from London about Russia's involvement in the poisoning is a problem.
While not offering public proof that Russia was behind the attack, Britain has invited the Organization for the Prohibition of Chemical Weapons (OPCW) to join its investigation of the incident. The organization began examining contaminated sites on March 21.
Russian officials have said they will not recognize the results of any investigation by the OPCW, however, if it does not involve information-sharing with Russia.
Sergei Skripal and his daughter Yulia, who had arrived from Moscow on March 3 to visit her father, were found collapsed on a bench in the southern English city of Salisbury the following day. They remain hospitalized and in critical condition.
Judge David Williams of the Court of Protection said on March 22 that their mental capacity may have been compromised to an "unknown" degree.
The court gave doctors permission to take blood samples from the Skripals to send to chemical-weapons experts.
A team from the Organization for the Prohibition of Chemical Weapons arrived in Britain this week.
Meanwhile, a police officer who fell ill after being exposed to the nerve agent was discharged from hospital.
Skripal is a former Russian military intelligence officer who was convicted of treason in 2006 after a court found that he passed the identities of Russian intelligence agents to Britain's Secret Intelligence Service, MI6.
He was one of four Russian prisoners released in 2010 in exchange for 10 Russian sleeper agents uncovered in the United States in one of the biggest spy swaps since the Cold War.