Minnesota Attorney General Lori Swanson is asking Congress to block President Donald Trump's tweeted ban on transgender troops serving in the military.

Nineteen state attorneys general wrote the House and Senate Armed Services committees this week asking them to write protections for transgender troops into the 2018 Defense Department budget that Congress is hammering out.

The president's proposal, the attorneys wrote Thursday, would violate American values as well as the Constitution and would harm transgender residents in their states as well.

"The new policy is also blatant discrimination," the attorneys general wrote. "It has no place in our Armed Services. It is an insult to the courageous transgender service members who hold vital roles in our military and continue to make tremendous sacrifices for our country. Transgender individuals are valued members of our communities."

The House passed the $696 billion National Defense Authorization Act, but the Senate has not yet taken up the military budget bill.

Ban met with surprise

The president's proposed ban — delivered in a series of tweets on Wednesday — caught Congress and the Pentagon by surprise and left thousands of transgender troops and Defense Department employees unsure whether they still had jobs.

"After consultation with my Generals and military experts, please be advised that the United States Government will not accept or allow transgender individuals to serve in any capacity in the U.S. Military," Trump wrote in a series of three tweets. "Our military must be focused on decisive and overwhelming victory and cannot be burdened with the tremendous medical costs and disruption that transgender in the military would entail. Thank you."

Despite the president's declaration, Gen. Joseph Dunford, chairman of the Joint Chiefs of Staff, sent an internal memo to all military service chiefs, commanders and enlisted leaders, noting that "there will be no modifications" to existing policy for now. The Obama administration lifted the ban on transgender people serving openly in the military last summer.

U.S. Rep. Tim Walz, a Minnesota Democrat and veteran, blasted the ban and the president who proposed it.

"Our brave transgender troops currently serving this great nation are not a burden; they are American heroes," he said this week. "They volunteered to put their lives on the line for our freedom, and their service should be welcomed, celebrated, respected and honored. After 24 years of service as an enlisted soldier, I know what it takes to build cohesive teams in our military. This President, who hasn't served a day of his life in uniform, does not."

Swanson's office did not return a call for comment.

The Associated Press contributed to this report.

Jennifer Brooks • 202-662-7452