A preliminary injunction requested by Amazon was issued by Judge Patricia Campbell-Smith, barring the Department of Defense from starting work on the contract known as JEDI, according to a summary of the ruling available online.

Details of the ruling were sealed for unspecified reasons.

Amazon has alleged it was shut out of the deal because of President Donald Trump's vendetta against the company and is seeking testimony from the president and other top officials on the reasons for awarding the $10 billion US military cloud computing contract.

The 10-year contract for the Joint Enterprise Defense Infrastructure (JEDI) program will ultimately see all military branches sharing information in a cloud-based system boosted by artificial intelligence.

An earlier court filing by Amazon detailed alleged errors that ended with Microsoft being chosen over its Amazon Web Services (AWS) cloud computing division, part of the technology group led by Jeff Bezos -- a frequent target of the president.

- Microsoft confident -

Microsoft said it hoped to prevail after the merits of the case are heard in court.

"We have confidence in the Department of Defense, and we believe the facts will show they ran a detailed, thorough and fair process in determining the needs of the warfighter were best met by Microsoft," Microsoft vice president of communications Frank Shaw said.

Amazon did not immediately respond to a request for comment.

Amazon was considered the lead contender to provide technology for JEDI, with AWS dominating the cloud computing arena and the company already providing classified servers for other government agencies including the CIA.

The Pentagon's mistakes in the contract were "hard to understand and impossible to assess" when separated from Trump's "repeatedly expressed determination to, in the words of the president himself, 'screw Amazon,'" court documents filed by Amazon argued.

Bezos, who also owns The Washington Post, is a frequent target of the US president, who claims the newspaper is biased against him.

The bid protest filed in US Court of Federal Claims urges that the rival JEDI bids be re-evaluated and a new decision reached.

As a condition of the injunction, Amazon was directed to provide $42 million that would be used to cover any costs or damages incurred if it is determined that the injunction was issued wrongly.