Updated at 9:50 a.m. ET
Russia says it will retaliate against Britain's recently announced sanctions, saying that President Vladimir Putin will soon decide the best way to respond to the U.K.'s expulsion of 23 Russian diplomats. It's the latest escalation in the clash between the two nations over the use of a military-grade nerve agent against a former Russian spy who is now a British citizen.
"A final decision [on retaliatory measures] will, of course, be made by the president of the Russian Federation," presidential spokesman Dmitry Peskov said, according to state-run Tass media. "There are no doubts that he will choose the variant that best of all corresponds to the interests of the Russian Federation."
Russian Foreign Minister Sergey Lavrov said, "The response will come very quickly, I can assure you," Tass reports.
Also on Thursday, the U.K. released a joint statement along with the U.S., France and Germany, calling on Russia to answer for the use of a poison developed in its Novichok chemical weapons program.
From the statement:
"This use of a military-grade nerve agent, of a type developed by Russia, constitutes the first offensive use of a nerve agent in Europe since the Second World War. It is an assault on U.K. sovereignty and any such use by a State party is a clear violation of the Chemical Weapons Convention and a breach of international law. It threatens the security of us all."
Prime Minister Theresa May has said Russia is guilty of attempted murder on British soil. Russia denies the charge despite the use of a nerve agent that is seen as its exclusive property to attack former Russian spy Sergei Skripal and his daughter last week.
On Thursday, the leaders of France, Germany and the U.S. stated, "We share the U.K. assessment that there is no plausible alternative explanation, and note that Russia's failure to address the legitimate request by the U.K. government further underlines its responsibility."
Britain announced sanctions on Wednesday, canceling high-level meetings and a royal visit to Russia for this summer's World Cup and banning Russians whom the U.K. has "identified as undeclared intelligence officers."
When the question of Russia's response came up at the Russian Foreign Ministry's weekly briefing on Thursday, spokesperson Maria Zakharova said:
"The head of a nuclear state goes to the Parliament ... they take an important step that they can't take. They accuse Russia of aggression against their country, and they issue 20-hour ultimatum. They just are detached from their reality, which is very dangerous. They are totally detached from their reality, they ignore the real consequences. It seems to us it's a 'talk show' that does not imply any communications, any international rules" but is instead a way to express an opinion.
Referring to the risks involved, Zakharova spoke of "the understanding that the people who come to power, they are irresponsible. And this is happening in many states."
She also accused May of using Russia to enhance her standing in the U.K., adding that the prime minister "wants to look like a strong leader, but we see that she's a different leader. And I don't think it's necessary for me to give any evaluation about that."
As the tit-for-tat exchange between Russia and the U.K. has intensified, May and Foreign Secretary Boris Johnson have been working to align their allies with the U.K.'s stance, talking with French President Emmanuel Macron, German Chancellor Angela Merkel and President Trump.
The conversations earlier this week seem to have had an effect — particularly in the U.S.
Hours before Trump issued what amounted to a "you're fired" tweet directed at Rex Tillerson earlier this week, the secretary of state had publicly called out Russia as the source of a nerve agent attack on an ex-spy in Britain.
In doing so, Tillerson went further than White House press secretary Sarah Huckabee Sanders, who earlier the same day had condemned the attack but made no mention of Russia.
That led to speculation that Tillerson's firing and his harsh words on Russia ("we are outraged that Russia appears to have again engaged in such behavior") may have been linked.
The Trump administration on Wednesday appeared to be eager to dispel that notion, with the State Department issuing a pair of statements that took a harder line against Moscow and with U.S. Ambassador to the United Nations Nikki Haley condemning Moscow at the Security Council.
Trump has been conspicuous in not condemning Russia — either in his public statements or on his prolific Twitter feed — even after Britain's stern response to the poisoning of Skripal, the 66-year-old Russian ex-spy and his 33-year-old, daughter, Yulia, who fell ill at a shopping center in southern England earlier this month.
"Where Prime Minister [Theresa] May has taken bold and decisive initial action to combat Russian aggression, our own president has waffled and demurred," Senate Minority Leader Chuck Schumer said in a statement on Wednesday. "Prime Minister May's decision to expel the Russian diplomats is the level of response that many Americans have been craving from our own administration."
The American leadership's tone on the issue went through an abrupt change after a telephone conversation Tuesday night between Trump and the British prime minister, with the White House issuing a statement afterwards expressing solidarity with the U.K. According to a readout on the conversation from May's office, "President Trump said the U.S. was with the U.K. all the way," as NPR reported.
Moreover, in words echoing earlier comments by Tillerson, State Department Acting Undersecretary for Public Affairs Heather Nauert, said: "The United States shares the United Kingdom's assessment that Russia is responsible for the reckless nerve agent attack on a British citizen and his daughter, and we support the United Kingdom's decision to expel Russian diplomats as a just response."
Nauert — who was elevated to acting undersecretary after the firing of Steve Goldstein, himself collateral damage of the Tillerson dismissal — went on to say, "This latest action by Russia fits into a pattern of behavior in which Russia disregards the international rules-based order, undermines the sovereignty and security of countries worldwide, and attempts to subvert and discredit Western democratic institutions and processes."
Speaking at an emergency Security Council session, Haley on Wednesday also named Russia, saying it was "responsible for the attack on two people in the United Kingdom using a military-grade nerve agent" and calling the attack "an atrocious crime."
In yet another statement from the State Department, Nauert condemned Russia's March 18, 2014, annexation of Crimea, calling the referendum used by Moscow as a pretext for the move "fabricated."
"Crimean residents were compelled to vote under scrutiny by heavily armed Russian troops. Russia's claim that Ukrainians made a free choice in that sham 'referendum' has always lacked credibility," she said in a statement.
"In his campaign rally in Crimea today, President Putin reiterated Russia's false claims to Ukrainian territory in another open admission that the Russian government disdains the international order and disrespects the territorial integrity of sovereign nations," Nauert said.
"Over the past four years, Russia has engaged in a campaign of coercion and violence, targeting anyone opposed to its attempted annexation," she said.
On Thursday, Lavrov had a different estimation of what is behind the friction between Russia and the U.S. and Britain, citing what he called the "categorical reluctance of the United States and its Western allies to agree that the 500-year-long period of Western domination in world affairs is coming to an end."
The change was painful, he said, for nations that "are in the habit of ruling the roost."