Secretary of Defense Pete Hegseth did not inform the White House before he authorized a pause on weapons shipments to Ukraine last week, according to five sources familiar with the matter, setting off a scramble inside the administration to understand why the halt was implemented and explain it to Congress and the Ukrainian government.

The Pentagon last week announced that it would hold back some weapons pledged to Ukraine because of what U.S. officials said were concerns that American stockpiles were in short supply.