It is the ultimate symbol of chest-thumping American patriotic pride and now the United States flag must be "100 percent made in the USA" -- at least where the Pentagon is concerned.

A new law requires the Department of Defense -- a major consumer of flags for everything from ships to bases to burials -- fly only flags wholly sourced from home shores.

"My recently signed law makes sure every flag bought by the US Department of Defense is 100 percent Made in America, with American products," Congressman Mike Thompson, whose district is home to a manufacturer of flags, wrote on his Facebook page.

"Our men in women in uniform should serve under American-made flags like those made at NBI, and our tax dollars should be spent on American-made flags," the Vietnam war veteran said.

The move -- effective last Friday -- garnered generally warm praise on Facebook.

One user, identifying himself as another Vietnam veteran, wrote: "Way to go!! Great job thank you. Wish List. Can we do it with other products as well? No Vets coffin should be draped in a cheap rag made over seas."

Although flags were already made by US companies, their material -- such as fabric and ink -- previously could have come from abroad.