Britain has hailed the mass expulsion of suspected Russian spies around the world as a "turning point," while Russia asserted that the expulsions were the result of "colossal pressure" by the United States.
The coordinated expulsions came in response to the poisoning of Russian double agent Sergei Skripal and his daughter Yulia with a nerve agent in the English city of Salisbury on March 4.
At least 116 diplomats were ordered out by 22 governments on March 26, followed by an additional expulsion of a Russian diplomat announced by Ireland on March 27, dwarfing even similar measures taken during Cold War spying disputes.
"Never before have so many countries come together to expel Russian diplomats," British Foreign Secretary Boris Johnson wrote in The Times, calling it "a "blow from which Russian intelligence will need many years to recover."
"I believe that yesterday's events could become a turning point," Johnson wrote, adding, "The Western alliance took decisive action and Britain's partners came together against the Kremlin's reckless ambitions."
Russian Foreign Minister Sergei Lavrov accused Washington of applying "colossal" pressure on allies to expel its diplomats, and vowed to respond to the move.
"This is the result of colossal pressure, colossal blackmail which is the main instrument of Washington on the international arena," Lavrov said during a visit to Uzbekistan.
"We'll respond, have no doubt! No one wants to put up with such loutish behaviour and we won't," Lavrov said, reiterating Moscow's warning that it was preparing a tit-for-tat response.
Sergei Skripal, a Russian military intelligence officer imprisoned by Moscow after being convicted of passing on information about Russian agents in various European countries, came to Britain in a 2010 spy swap.
Britain earlier ordered the expulsion of 23 Russian diplomats after blaming Moscow for the attack on Skripal and his daughter, who remain in critical condition. Moscow has fiercely denied the charge and has pointed the finger at British intelligence.
Britain's allies followed suit, with Washington leading the way by ordering out 60 Russians in a new blow to U.S.-Russia ties less than a week after President Donald Trump congratulated Russian President Vladimir Putin on his reelection.
Many EU countries also ordered Russian diplomats out. Germany, France, and Poland each expelled four; the Czech Republic and Lithuania each expelled three; Spain, the Netherlands, Denmark, and Italy each expelled two; and Hungary, Sweden, Croatia, Romania, Finland, Latvia, and Estonia announced plans to expel one Russian diplomat each.
Outside the EU, Canada, Australia, Ukraine, Macedonia, and Norway also announced expulsions.
On March 27, Ireland followed suit, becoming the latest country to order out a Russian diplomat, Ireland's Foreign Ministry said in a statement.
"The attack in Salisbury was not just an attack against the United Kingdom but an affront to the international rules-based system on which we all depend for our security and wellbeing," the statement said.
Also on March 27, British Prime Minister Theresa May told senior ministers that there was still more to be done in Britain's long-term response to Russia.
"Yesterday was a significant moment in our response to this reckless act of aggression, but there is still more to be done as we work with international partners on a long-term response to the challenge posed by Russia," her spokesman said, reporting remarks made by May at a cabinet meeting.
NATO chief Jens Stoltenberg will also unveil "measures" on March 27 in connection to the Skripal case at a news conference in Brussels, the alliance said in a brief statement.
Western officials made it clear in announcing the expulsions that they share Britain's assessment that only the Russian state could have been behind the incident.
In his article for The Times, Johnson said the attack fell into pattern of "reckless behavior" by Putin, including the annexation of Crimea.
"The common thread is Putin's willingness to defy the essential rules on which the safety of every country depends," he said.
"Hence every responsible nation shares a vital interest in standing firm against him," he said.
Johnson also accused Russia of seeking to avoid pressure by putting out a variety of explanations for what Western officials say was the first offensive use of a chemical weapon in Europe since World War II.
"There was a time when this tactic of sowing doubt might have been effective, but no one is fooled any more. I believe yesterday was a moment when the cynicism of the propaganda machine was exposed for all to see," he said.
U.S. officials announced that 48 "intelligence officers" attached to Russian diplomatic missions in the United States would be expelled, along with 12 accredited to the United Nations in New York.
This was the largest U.S. expulsion of Russian or Soviet agents ever and comes after Trump's predecessor Barack Obama expelled 35 in late 2016 over alleged election meddling.
In addition, the Russian consulate general in Seattle will be closed, the White House said.
The Russian Embassy in Washington asked its Twitter followers to vote on which U.S. consulate should be closed in response to the closing of the Russian consulate in Seattle, listing those in Vladivostok, St. Petersburg and Yekaterinburg as options.