The U.S. government began to shut down for the first time in 17 years early Tuesday, after a Congress bitterly divided over President Obama’s signature health-care initiative failed to reach an agreement to fund federal agencies.

It was predicted that the closure would last at least a week.

Hours before a midnight deadline, the Republican House passed its third proposal in two weeks to fund the government for a matter of weeks. Like the previous plans, the new one sought to undermine the Affordable Care Act, this time by delaying enforcement of the "individual mandate," a cornerstone of the law that requires all Americans to obtain health insurance.

The new measure also sought to strip lawmakers and their aides of long-standing government health benefits.

The Democratic-led Senate quickly rejected that plan on a party-line vote. Senate Majority Leader Harry M. Reid, D-Nev., urged House Speaker John A. Boehner, R-Ohio, to abandon the assault on the health-care law and pass a simple bill to keep the government open. Otherwise, Reid warned, "the responsibility for this Republican government shutdown will rest squarely on his shoulders."

Boehner refused to yield. He instead won approval, in a 1 a.m. largely party-line roll call, requesting a special House-Senate committee to meet in the coming days to resolve differences between the two parties, leaving in limbo the fate of millions of federal workers and the services they provide.

Shortly before midnight, the White House budget office issued a memo instructing agencies to "execute plans for an orderly shutdown due to the absence of appropriations."

The impasse means 800,000 federal workers will be furloughed. National parks, monuments and museums, as well as most federal offices, will close. Tens of thousands of air-traffic controllers, prison guards and Border Patrol agents will be required to serve without pay. And many congressional hearings — including one scheduled for Tuesday on last month’s Washington Navy Yard shootings — will be postponed.