ROME, Italy (AFP) — Italy on Friday defended blocking a shipment of coronavirus vaccines to Australia, saying such action towards less affected countries was legitimate while it was facing "unacceptable" delivery delays.

Foreign Minister Luigi Di Maio insisted the decision "was not a hostile act" towards Australia, pointing out that the blockade was carried out under European Union rules.

Rome revealed on Thursday it had blocked the export of 250,700 doses of AstraZeneca's COVID-19 vaccine meant for Australia, blaming the shortage of jabs in virus-hit Europe -- and the lack of urgent need in Australia.

Asked about the issue at a press conference in Rome, Di Maio cited first the "unacceptable delays" in delivery of vaccines and the threat from the more contagious UK variant of coronavirus sweeping across Italy and other parts of Europe.

"As long as there are these delays, it is right for European Union countries to block exports to countries which are not vulnerable," he said.

Australia's government said the absence of that one shipment would not affect its rollout of the AstraZeneca vaccine that started on Friday.

However, Prime Minister Scott Morrison said he would ask Brussels to review the decision, the first under an EU scheme that began in January.

A company wanting to export doses out of the EU needs to apply to the national government, which can block the export provided Brussels agrees.