Tensions have escalated over coronavirus vaccines in Europe as France accused the UK of "blackmail" over its handling of vaccine supplies.
European Union countries have said they are not receiving supplies of the shot promised by AstraZeneca, among others, and have alleged Britain has been getting more than its fair share.
France's foreign minister Jean-Yves Le Drian on Friday claimed the UK had focused on rolling out first doses and will struggle to source second jabs.
But he suggested that Brussels would not be "blackmailed" into giving up doses to solve the UK's problem.
"We need to achieve a relationship of cooperation with the United Kingdom so AstraZeneca fulfils its commitments, signed with the European Union, and everyone gets what they need," Le Drian told France Info television in an interview.
"But one cannot play like that, a kind of blackmail, where you wanted to vaccinate with all your might with the first dose and then you find yourself handicapped with the second doses."
The UK has said it does not believe in imposing vaccine blockades and that the EU must allow COVID-19 vaccine contracts to be fulfilled.
The EU this week tightened its oversight of coronavirus vaccine exports, giving it more scope to block shipments to countries with higher inoculation rates.
British foreign minister Dominic Raab hit back, accusing the European Commission of brinkmanship.
In a move that may ease the situation, the European Medicines Agency on Friday approved new manufacturing sites for coronavirus vaccines made by Pfizer, Moderna and AstraZeneca.
Meanwhile, large parts of Europe continue to struggle with a third wave of COVID-19 infections, putting hospitals under pressure and prolonging restrictions.
Germany warned its citizens on Friday not to make unnecessary trips to neighbouring France, Austria, Denmark and the Czech Republic because of rising infection rates.
Germany also declared all of France as a "high incidence area" for the coronavirus, meaning people travelling from France must provide a negative test before crossing the German border.
Poland's authorities have vowed strict enforcement of new restrictions and stiff fines, calling the situation "dramatic" as the nation registered a record number of new cases for the third straight day.
And the Czech parliament extended a state of emergency on Friday giving the government extra powers to fight pandemic until April 11 as it seeks to start reopening schools.