Russia has lashed out at Britain ahead of an expected announcement by Prime Minister Theresa May on measures against Moscow, which ignored a midnight deadline to explain how a nerve agent developed during the Cold War was used to poison a former Russian spy in Britain.
The United States, European Union, and NATO all said they supported Britain after May said it was "highly likely" that Russia was behind the poisoning of Sergei Skripal and his daughter with a deadly chemical substance developed by the Soviet military -- part of a group of nerve agents known as Novichok.
May gave Moscow a deadline of midnight on March 13 to explain how the rare nerve agent made its way to England. She said she is reviewing a range of economic and diplomatic measures in retaliation for the assault.
The prime minister is due to host a meeting of her national security council. She is then expected to give an update to lawmakers.
British news reports said measures could involve the expulsion of Russian diplomats, sanctions against Russians with links to the Kremlin, curbs on Kremlin-backed broadcaster RT, and a boycott of the World Cup soccer tournament in Russia this summer.
A few hours before the expected announcement, President Vladimir Putin's spokesman reiterated Russia's denial of involvement, saying that Moscow is in no way connected to the poisoning and will not accept "unfounded” accusations or ultimatums.
Spokesman Dmitry Peskov expressed hope that any measures by London will be based on "common sense," warning that actions against Moscow will trigger a response. He did not elaborate.
Meanwhile, Russian Foreign Minister Sergei Lavrov accused Britain of “acting out a political drama” to mislead the international community.
He argued that Russia had no motive to attack Skripal and said the poisoning could have been plotted by people or groups with an interest in spreading “Russophobic” sentiment.
Despite May's demand, Lavrov said that London has not sent an official request for information about the nerve agent involved in the attack.
He had earlier said that his country's requests to see samples of the nerve agent have been turned down.
British police said the probe into the poisoning of Sergei Skripal, 66, and Yulia Skripal, 33, will last many weeks and that they are not ready to identify any persons of interest in the inquiry.
The two remained in critical condition in a hospital in the southern English city of Salisbury, where they were hospitalized on March 4 after being found unconscious on a bench outside a shopping mall.
London has called for an urgent meeting of the UN Security Council to update members on the investigation into the poisoning, the Foreign Office said on March 14.
NATO’s main decision-making body, the North Atlantic Council, expressed "deep concern at the first offensive use of a nerve agent" on alliance territory since NATO was founded in 1949.
In a statement, the allies called on Russia to answer Britain's questions in full about the Novichok nerve agent.
European Council President Donald Tusk said EU leaders would discuss the matter at their meeting next week, adding that the incident showed the need for "transatlantic unity."
In Geneva, the head of the British mission to the UN there, Julian Braithwaite, told the Human Rights Council that Russia’s “reckless behavior is an affront to all this body stands for."
"From Ukraine to Syria, and now the United Kingdom, Russia continues to be an irresponsible force of instability in the world,” said Jason Mack, a first secretary at the U.S. mission in the Swiss city.
The White House joined Britain in calling on Russia to provide "unambiguous answers regarding how this chemical weapon, developed in Russia, came to be used in the United Kingdom," after a phone call between May and U.S. President Donald Trump on March 13.
"The two leaders agreed on the need for consequences for those who use these heinous weapons in flagrant violation of international norms," it said.
French President Emmanuel Macron and German Chancellor Angela Merkel also condemned the attack and offered support to Britain.
A Russian chemist who helped develop the nerve agent in the Soviet era and now lives in the United States said that only the Russian government could have carried out the attack with such a deadly and advanced toxin.
Vil Mirzayanov, 83, said that Russia maintains tight control over its Novichok stockpile and that the agent is too complicated for a nonstate actor to have weaponized.
“The Kremlin all the time, like all criminals, denying -- it doesn’t mean anything,” Reuters quoted Mirzayanov as saying in an interview at his home in Princeton, New Jersey.
Meanwhile, British broadcasting regulator Ofcom has warned it could review RT's license.
Ofcom said it had written to ANO TV Novosti, which holds RT's British broadcast licenses, saying that if Moscow is found to be behind the attack, "we would consider this relevant to our ongoing duty to be satisfied that RT is fit and proper."
In response to Ofcom's statement, Moscow threatened on March 13 to bar all British media from working in Russia if British authorities ban RT.
"No British media will work in Russia if they close down RT," Russian Foreign Ministry spokeswoman Maria Zakharova said.
Skripal, a retired Russian military intelligence colonel, was convicted by a Moscow military court in 2006 of "high treason" for passing secrets to Britain's Secret Intelligence Service.
He was one of four Russian prisoners released in 2010 in exchange for 10 Russian sleeper agents detained in the United States in one of the biggest spy scandals since the Cold War.
Police have confirmed that Sergei Skripal is a British citizen. Lavrov said that Yulia Skripal has Russian citizenship.
With reporting by AP, AFP, dpa, and Reuters