House Speaker Paul Ryan on Tuesday blasted the Defense Department for cooking up a plan to defeat his defense authorization bill, and said it shows the Obama administration just wants to play politics instead of working to protect and fund U.S. troops.

"For this administration, it's always politics first, even at the Pentagon," Ryan said.

Ryan was reacting to a mid-May memo that explains how Obama administration officials should fight Ryan's plan to boost defense spending in a way that avoids congressional budget caps. Republicans are again expected to boost spending by authorizing billions more in the overseas contingency operations budget, which is used for war operations.

Democrats have criticized this move before, because it gives the Defense Department a way around congressional spending caps that other social spending programs can't use.

But Ryan said the elaborate plan described by the Defense Department shows officials aren't negotiating in good faith.

"This memo details with relish a plan to use a presidential veto of a defense bill as a 'weapon,'" he said. "It's shameless, and it threatens more than five decades of bipartisan cooperation to enact a national defense bill for our troops. The men and women who defend our country deserve better."

House Armed Services Committee Chairman Mac Thornberry, R-Texas, said it's "unfortunate" that the Defense Department would spend time playing "political games."

"In a Department charged with the security of our nation, the American people and our troops deserve better," he said.

The May 13 memo, first reported by Politico, calls on officials to seek out Republicans in Congress to fight the plan, including Sen. John McCain, R-Ariz.

It also calls on officials to label the move as a "gimmick," and encourages Defense Secretary Ash Carter to meet with Democrats and convince them to vote down the bill.