WASHINGTON (AP) — Members of the Joint Chiefs of Staff say the billions of dollars in defense budget cuts scheduled to begin at the end of the week will have a swift and severe impact on military readiness and they urged Congress to take fast action to stop the reductions.

Testifying Tuesday before a House subcommittee, the uniformed leaders of the military branches described how national security would be put at risk if they are forced to make deep decreases in spending for personnel, training, and equipment modernization programs.

The budget cuts are scheduled to go into effect on Friday. The Pentagon faces a $46 billion budget reduction through the end of September, and billions of dollars in additional cuts would come in future years as long as the sequester remains in effect.