WASHINGTON (AP) — President Bush took executive action on Tuesday to crack down on pork barrel practices in Congress. He promised to veto any spending bill that doesn't cut the number and cost of congressional pet projects in half.

The executive order Bush signed in the Oval Office orders federal agencies to ignore "earmarks" that aren't explicitly enacted into law, erasing a common practice in which lawmakers' projects are outlined in nonbinding documents that accompany legislation.

"That means that these projects never were voted on, never really saw the light of day," Bush said as he signed the order that he announced in his State of the Union address Monday night.

Bush, however, has disappointed some conservatives by backing away from a veiled threat issued last month in which he seemed to suggest he would kill some or all of the thousands of earmarks contained in last year's huge omnibus appropriations bill.

His executive order won't apply to the thousands of earmarks that accompanied a massive spending bill he signed last month.