SIMI VALLEY, Calif. — The Pentagon is in discussions with Congress about pivoting away from technology development programs that may no longer be relevant, the building’s top acquisition official said Saturday.

Ellen Lord, the undersecretary of defense for acquisition, technology and logistics, said the building is having “very difficult discussions” with the Hill about pivoting away from some programs in order to redirect funding to more vital systems, as it grapples with both changing global environments and the ongoing specter of sequestration.

“We need to continue the dialogue with Congress because the world’s shifting around us and sometimes we need to redirect our investments,” Lord told an audience at the Reagan National Defense Forum. “And that’s a tough thing to do sometimes, when you have to say what I decided I was going to do three years ago that were in the best interest of our nation perhaps isn’t now, and It’s always hard to stop something.

“It’s hard. And it’s hard for Congress to go back to their constituents and say ‘guess what, we’re going to stop this right now, even though it’s in your district,’” Lord acknowledged.

Lord did not go into details about what programs are under discussion, but did offer at least one area where she believes investments would pay off for the department in the future — hypersonic weapons.

“We are generating capability, there are programs within DARPA, there are programs within [the Office of the Secretary of Defense], where we are generating new weapons that fly differently and that fly very fast that I think are going to be significant in our ability to really have an advantage over adversaries,” Lord said.

For the fact the DoD already has hypersonic programs underway, Lord offered thanks to the previous Pentagon team, especially former Deputy Secretary of Defense Bob Work and his “Third Offset” strategy.

“If the prior administration hadn’t had that foresight and laid out that vision I don’t think we would be where we are today,” Lord said.