French President accuses Moscow over UK spy poisoning
France had repeatedly expressed its solidarity with Britain over the poisoning of Sergei Skripal and his daughter Yulia in the English city of Salisbury, but had declined to point the finger directly at Moscow.
Comments from a government spokesman on Wednesday, who said France was waiting for more proof, had raised doubts about whether Paris would join a coordinated response against Moscow, as called for by London.
Seeking to clarify France's position, Macron told reporters that he condemned "in the strongest possible terms this unacceptable attack".
"Everything leads us to believe that responsibility can be attributed to Russia, and the work of the British services, shared with France's services, confirms it," he said during a visit to the wine-growing Loire region in central France.
"I will announce the measures that we are going to take in the coming days," he said, with any announcement set to come after his talks with German Chancellor Angela Merkel on Friday in Paris.
British Prime Minister Theresa May, who announced the expulsion of 23 Russian diplomats on Wednesday, has called for her allies to show a united front against what she considers another Russian aggression.
Moscow has denied any responsibility and has pledged to respond to the expulsions by Britain.
Trying to build ties with Putin
Since his election in May last year, Macron has invested time and energy in trying to build a relationship with Putin, seeing him as crucial to resolving conflicts in Syria and Ukraine.
Despite allegations that Russia intervened to help his opponents in the French election last year, the 40-year-old French president welcomed Putin in the former seat of royal power in Versailles in May in a bid to reset ties.
Macron is scheduled to return the compliment by visiting Saint Petersburg and possibly Moscow in May.
Doubts about France's commitment to backing up Britain led The Times of London newspaper to run a front-page headline "France defies Theresa May over punishment of Russia" on Thursday.
Macron's office put out a statement hours later saying he had spoken again with May and that France "shares Britain's assessment that there is no other plausible explanation" that Russia being responsible.
Britain's ambassador to France, Ed Llewellyn, called it a "strong statement of support".
Britain's desire for back-up from its European neighbours comes at a difficult time as the country is negotiating to leave the European Union following its referendum in 2016.
The Brexit talks on a divorce deal and future trading relationship have strained ties Britain's European allies.
"Any reasonable person looking at this terrible attack would come to the conclusion that Brexit is a completely different thing," Francois Heisbourg, the head of the International Institute for Strategic Studies in London, told AFP earlier this week.
"You will always find some Schadenfreude among some people, but chemical weapons are a serious thing," added the former French diplomat.
A possible coordinated EU response will come up at a summit of all 28 leaders including May in Brussels next week.
The bloc imposed the first of a series of sanctions on Russia in 2014 over its annexation of Crimea.
Any further sanctions would require unanimous support.
JOIN OUR PULSE COMMUNITY!
Eyewitness? Submit your stories now via social or:
Email: eyewitness@pulse.ng