(AP Photo/Pool-Michael Reynolds)
"Not a single thing he said is accurate," Democrat Biden declared in the opening moments of the only debate between the vice presidential candidates in a national campaign with a little less than four weeks left to run.
Both men seemed primed for a showdown from their opening moments on stage, and neither seemed willing to let the other one have the final word.
Ryan said the administration had accorded insufficient security to Ambassador Chris Stevens, who was killed in a terrorist attack at the U.S. Consulate in Benghazi on Sept. 11
Biden said the budget that Ryan authored as chairman of the House Budget Committee had cut the Obama administration's funding request for diplomatic security by $300 million.
The men also tangled over the wars in Iraq and Afghanistan, administration steps to prevent Iran from developing a nuclear weapon and relations with Israel, an area in which Republican presidential candidate Mitt Romney frequently accuses President Barack Obama of letting down the United States' closest ally in the Middle East.
Biden, 69, repeatedly accused Ryan of misstating the facts -- "this is a bunch of stuff," he erupted at one point.
But the 42-year-old Wisconsin congressman stood his ground. Iran is "four years closer" to having a nuclear weapon as Obama's term nears its end, he said.
The debate took place a little more than a week after Obama and Romney met in the first of their three debates -- an encounter that has fueled a Republican comeback in the polls.
With Democrats eager for Biden to show the spark the president lacked, he did so early and often.
Unprompted, he brought up the videotape where Romney had said 47 percent of Americans pay no federal income tax and view themselves as victims who do not take responsibility for their own lives.
"It's about time they take responsibility" instead of signing pledges to avoid raising taxes, Biden said of Romney, Ryan and the Republicans.
But Ryan quickly recited the economic statistics -- 23 million are struggling to work, he said, and 15 percent of the country is living in poverty. "This is not what a real recovery looks like."
Romney has gained ground in national and battleground-state surveys in the week since he shared a stage with the president, and even Obama has conceded he performed poorly.
Asked pointedly when they could reduce unemployment to 6 percent from the current 7.8 percent, neither man answered directly.
Instead, Biden repeated the president's contention that the nation is moving in the right direction, while Ryan repeated the Republican view that economic struggle persists even though Democrats had control of both houses of Congress during the first two years of Obama's term.
"Where are the 5 million green jobs" we were told would be created? Ryan asked Biden.
Republicans and Democrats alike have said in recent days the race approximates the competitive situation in place before the political conventions.
The presidential candidates, in general, are separated by a point or two in national public opinion polls and in several battleground states, with Obama holding a slender lead in Ohio and Wisconsin.