"All of us who live in this country depend on its strong defense," Microsoft president Brad Smith said in a blog post.

"Today the citizens in our military risk their lives not only as the country's first line of defense, but often as the nation's first line of assistance around the world in hurricanes, floods, earthquakes and other disasters."

The statement came two weeks after Google dropped out of the bidding for the huge Pentagon cloud computing contract that could be worth up to $10 billion. The company said the deal would be inconsistent with its principles, which left Amazon and Microsoft as two leading contenders.

Smith said Microsoft has been a longstanding supplier of technology for the US military, and added that the company was aware of the potential ethical concerns about the use of artificial intelligence in warfare.

"We appreciate that technology is creating new ethical and policy issues that the country needs to address in a thoughtful and wise manner," Smith wrote.

"But we can't expect these new developments to be addressed wisely if the people in the tech sector who know the most about technology withdraw from the conversation."

Smith said he and chief executive Satya Nadella clarified Microsoft's position in a conversation with employees, and acknowledged "that some of our employees may have different views" on the matter.

He said that Microsoft would respect the position of employees who did not want to work on a military project and would offer the option of shifting jobs where possible.

Smith said Microsoft is maintaining its bid for the Joint Enterprise Defense Infrastructure (JEDI) contract aimed at modernizing the military's computing systems.

Earlier this month, Google said it was dropping its JEDI bid in part because "we couldn't be assured that it would align with our AI principles" unveiled this year. Those points state the company would steer clear of "technologies that cause or are likely to cause overall harm" and "weapons or other technologies whose principal purpose or implementation is to cause or directly facilitate injury to people."

Amazon CEO Jeff Bezos said recently his company would maintain its JEDI bid, saying it was important to support US defense efforts even if unpopular.

"This is a great country and it does need to be defended," Bezos said at the Wired 25th Anniversary conference in San Francisco.