Moscow said on Wednesday that Britain chose a confrontation with Russia after it decided to expel 23 of its diplomats from London in wake of the poisoning of former spy Sergi Skripal. "The British government made a choice for confrontation with Russia," the Russian foreign ministry said in a statement, vowing that a retaliation will soon follow. British Prime Minister Theresa May on Wednesday expelled the diplomats and suspended high-level contacts with Russia after Moscow did not respond to her demand for an explanation on how a Soviet-designed nerve agent came to be used to attack Skripal on British soil. May said there was "no alternative conclusion other than that the Russian state was culpable" for the attack on Skripal and his daughter, who fell ill from exposure to a substance called Novichok in the city of Salisbury on March 4 and are currently in hospital. The Russian ministry said Mays statement was an "unprecedentedly rude provocation which undermines the foundations of normal bilateral dialogue between our countries." It accused London of pursuing a political agenda and choosing to "aggravate relations," calling the announced measures "hostile". May also confirmed that neither members of the royal family nor ministers would attend the football World Cup in Russia this year. "Our response measures will not be tardy," the Russian foreign ministry said. Dmitry Peskov, spokesman for President Vladimir Putin, told reporters that Russia "rejects the language of ultimatums" after May gave Russia until the end of Tuesday to explain how the Soviet-made nerve agent came to be used to target the ex-spy. Britain, which has received statements of support from the United States, the European Union and NATO, has said it would seek to coordinate an international response to the attack. German Chancellor Angela Merkel said she took the British findings seriously and there would be a common European stance, although “we must still talk responsibly” with Russia despite differences of opinion. A French government spokesman said Paris was awaiting proof before deciding if it would act in solidarity with London.