BRUSSELS (BLOOMBERG) - AstraZeneca bowed to pressure from the European Union and published its contract for the delivery of Covid-19 vaccines to the region as tensions escalate over an expected shortfall in supplies.

The text suggests that British manufacturing sites can be counted towards the company's manufacturing arrangements for the EU, which has been a subject of dispute between the bloc and the British drugmaker. But the contract says only that the company should exercise "best reasonable efforts" to resolve capacity problems arising from competing supply agreements.

"To the extent AstraZeneca's performance under this agreement is impeded by any such competing agreements, AstraZeneca shall not be deemed in breach of this agreement as a result of any such delay due to the aforementioned competing agreement(s)," the contract reads.

Details on the number of doses and delivery dates were redacted in the published version. The company and the EU had previously said their deal covered as many as 400 million doses to be delivered this year. AstraZeneca also has supply agreements with Britain, the United States and other countries.

The EU agreement is subject to Belgian law, according to the text of the contract.

Mr Pascal Soriot, AstraZeneca's chief executive officer, has said that once the company gets EU approval - expected on Friday (Jan 29) - it will ship at least three million doses immediately, with a target of 17 million by February.

Frustrations in Europe have mounted since AstraZeneca told the EU last week that shipments would be lower than expected in the first quarter due to a production glitch at a site in Belgium. European officials have demanded the company make up the shortfall using British supplies as the continent struggles to get its vaccination program up and running as quickly as Britain and the US.