WASHINGTON (Reuters) - With time quickly running out to raise the debt ceiling, the Obama administration is turning to biblical rhetoric to underscore the disastrous consequences if the United States defaults.

For weeks Treasury Secretary Timothy Geithner and other administration officials have been warning of an economic "catastrophe" if the $14.3 trillion debt ceiling, which caps the amount Washington can borrow, is not raised by August 2.

Merriam-Webster dictionary defines catastrophe as "a momentous tragic event ranging from extreme misfortune to utter overthrow or ruin."

That definition appears to chime with the view of most economists, who agree that a U.S. default on its obligations would plunge the United States into a new recession and send shockwaves through international financial markets.

In interviews, speeches and news conferences, administration officials have used the word again and again. But instead of scaring Republicans into action and breaking deadlocked debt talks it has had the opposite effect.

Republican lawmakers accuse the Obama administration of scaremongering and many refuse to budge from their firm belief that a default will not happen, that the United States can keep paying its creditors simply by cutting back on spending.

Americans also do not appear to share the Obama administration's sense of doom. Polls show a majority of Americans are happy for the debt ceiling not to be raised, although its not clear that those being surveyed are fully aware of the consequences of such a step.

WHEN CATASTROPHE IS NOT ENOUGH

So, the White House has upped the ante, eschewing catastrophe for a word more reminiscent of the "Cold War" stand-off between a nuclear-armed Soviet Union and United States -- Armageddon.

Obama used the biblical reference last week at a White House news conference when he talked about a complicated Republican plan that seeks to pin the blame for raising the debt ceiling on him. He said then it could avert economic Armageddon.

Obama's budget director, Jack Lew, repeated it during a television interview on Sunday.

"Notwithstanding the voices of a few who are willing play with Armageddon, responsible leaders in Washington are not, he told ABC's "This Week" program.

To be fair, it was a Republican, Senator Kay Bailey Hutchison, who first warned way back in April the debt ceiling negotiations would be a cataclysmic event, although at the time her warning was dismissed by many in Washington as hyperbole.

"The debt ceiling is going to be Armageddon," she said, trying to explain that while a just-ended budget dispute between Republicans and Obama had brought the government to the brink of a shutdown, the debt talks would be even worse.

Merriam-Webster's definition makes clear that while a catastrophe would be bad enough, Armageddon would be positively apocalyptic: "The site or time of a final and conclusive battle between the forces of good and evil; a usually vast decisive conflict or confrontation."