Republican lawmakers and conservative activists are expressing outrage after the Obama administration announced its objection to adding President Franklin Roosevelt's D-Day prayer to the World War II Memorial in Washington, D.C.

The objection was noted during a congressional hearing on Rep. Bill Johnson's, R-Ohio, bill -- the "World War II Memorial Prayer Act of 2011."

"It is unconscionable that the Obama administration would stand in the way of honoring our nation's distinguished World War II veterans," Johnson said. "President Roosevelt's prayer gave solace, comfort and strength to our nation and our brave warriors as we fought against tyranny and oppression."

Roosevelt asked the nation to join him in prayer as U.S. and allied troops launched the invasion that led to the defeat of Nazi Germany. He asked God to give the allied troops courage and faith, saying, "With thy blessing we shall prevail over the unholy forces of our enemy."

But Robert Abbey, the director of the Bureau of Land Management, said any plaque or inscription of the prayer would "dilute" the memorial's central message and therefore "should not be altered."

"It is not a judgment as to the merit of this new commemoration, simply that altering the Memorial in this way, as proposed in HR 2070, will necessarily dilute this elegant memorial's central message and its ability to clearly convey that message to move, educate, and inspire its many visitors," Abbey said in written testimony.

Abbey explained to lawmakers that altering the memorial would be contrary to the Commemorative Works Act -- a law that prohibits "encroachment by a new commemoration on a existing one." It also respects the design of the "completed work of civic art without alteration or addition of new elements."

Johnson told Fox News that the administration's objection should "give all Americans a great deal of concern."

"For there to be objections to demonstrating a faith in God at critical points in our nation's history -- particularly D-Day -- boggles my mind," Johnson said. "I was very surprised they were going to object."

Tony Perkins, president of the Family Research Council said it's not all that surprising.

"This is further evidence that the administration has created an environment that is hostile towards American history -- but in particular towards Christianity," Perkins told Fox News. "I hope America wakes up and realizes what this administration is doing to this country and how they want to radically and fundamentally change America."

"They want to erase every aspect of America's heritage," Perkins said of Obama's administration. "Any president, any official in history that has embraced Christianity, is no longer welcome in this administration. That's the environment they are creating."

Johnson's bill, which had bipartisan support, is expected to pass a committee vote and he anticipates the full House will support the legislation.

The Associated Press contributed to this report.