The first US government shutdown in 17 years has put a choke hold on Washington, with the White House and Republicans digging in for an extended struggle with no way out in sight.

National monuments were barricaded on Tuesday, US war cemeteries in Europe closed, and hundreds of thousands of federal workers were sent home without pay, after dawn revealed the wreckage of America's latest paralyzing political crisis.

President Barack Obama accused conservatives in the House of Representatives of waging an "ideological crusade" by making government funding conditional on gutting his landmark health care law.

His top foe, Republican House Speaker John Boehner, meanwhile claimed Obama was pursuing a "scorched earth" policy by refusing to negotiate, as the rhetoric hit new heights and hopes for a swift end to the standoff faded.

The president was in feisty form at a White House event marking the rollout of a key portion of Obamacare, which turned into an extended taunt at Republicans for failing to halt implementation of the sweeping law.

"This Republican shutdown did not have to happen -- I want every American to understand why it did happen," Obama said.

"They have shut down the government over an ideological crusade to deny affordable health care to millions of Americans."

It was the morning after on Capitol Hill, where late night brinkmanship sent America into its first government shutdown in 17 years when the money ran out at midnight.

Boehner, who effectively chose to side with the uproarious Tea Party faction of his party rather than risk his job by attempting to pass a straight funding resolution stripped of political poison pills, lit into the president.

"Washington Democrats have slammed the door on reopening the government by refusing to engage in bipartisan talks," he wrote in an opinion piece in USA Today.

The political paralysis remained unbroken as the Senate followed through on Majority Leader Harry Reid's promise, rejecting the House's demand that the two chambers appoint formal negotiators to thrash out a deal.

So far at least, Boehner is dancing on precarious political ground.

A Quinnipiac University poll found voters, by a margin of 72 percent to 22 percent, oppose the shutdown of the government as a way to derail Obamacare.

The New York Daily News tabloid had a more blunt summation: "House of Turds" its front page read, in a swipe at Republicans modeled on the hit Netflix political mini-series "House of Cards."

Thousands of federal workers trekked into town only to clear their desks and be told they were not "essential" to running the US government machine.

Young aides trooped out of the White House, leaving Obama with only a skeleton crew on hand.

Perplexed tourists were turned away from monuments and museums on the National Mall secured behind barriers and tape reading "Police Line: Do not Cross."

But one hardy group was made of sterner stuff -- an ageing band of the so-called Greatest Generation showed up at the World War II memorial and refused to be denied entry.

Those visiting their dead comrades in France, Belgium, Italy and elsewhere were turned away, as funding dried up for American cemeteries in 20 foreign fields.

Another symbol of hard-won freedoms -- The Statue of Liberty in New York -- was off limits to disappointed tourists.

The military and border patrol were kept at full strength, but the Pentagon was due to stand down almost half of its 800,000 civilian employees.

Warring lawmakers, exhausted by Monday night's political theatrics, stirred under the serene Capitol Rotunda, but early hopes that a compromise would emerge once the shock of the shutdown had hit proved premature.

House Republicans sought to pass a trio of measures funding popular parts of government, including veterans benefits and museums.

The plan appeared to be an attempt to shame Democrats who say they will not negotiate with "a gun to their head" with the government closed.

"That proposal shows the utter lack of seriousness that we're seeing from Republicans," said White House spokesman Jay Carney.

All three bills were defeated, heaping more pressure on Congress to end the stalemate.

Democratic leader in the Senate, Reid, added: "We won't be forced to choose between parks and cancer research... or the FBI."

Democratic tactics were designed to thwart every Republican attempt for a face-saving exit and to force an eventual climbdown by Boehner.

Obama warned that the shutdown could have disastrous consequences for America's sluggish economic recovery.

"We know that the last time Republicans shut down the government in 1996, it hurt our economy. And unlike 1996, our economy is still recovering from the worst recession in generations," the president said.

To highlight his case, Obama was due to meet CEOs of some top Wall Street firms at the White House on Wednesday.