White House challenger Mitt Romney seized upon a terrible jobs report to wrest back the agenda of the US presidential race, after Barack Obama's week in the convention spotlight. Both candidates hit the campaign trail immediately after the Democratic National Convention ended, but the president was put on the back foot by poor reviews of a major speech and the latest bad economic news. Romney, who flew into the battleground farming state of Iowa just ahead of Obama, took the opportunity to twist the knife and win himself some coverage after three days dominated by the Democrats' jamboree. "I was surprised by his address because I expected him to confront the major challenge of the last four years, which is an economy which has not produced the jobs that the American people need," the Republican hopeful said. As Democrats left Charlotte, the North Carolina city that hosted their gala, their upbeat mood was dented by Friday's report from the Labor Department, which revealed that just 96,000 jobs were created last month. This was fewer than many observers expected, and the number was seized upon by Republicans as evidence that Obama does not deserve another four years in office struggling to get the economic recovery back on track. "I expected him to talk about those things, but he did not," Romney said. "Instead, it was a whole series of new promises which he also won't be able to keep. If President Obama were re-elected, we would have four more years of the last four years, and the American people are going to say no to that." The flat report cast a shadow over the president's post convention tour of New Hampshire, Iowa and Florida, and could trim any opinion poll bounce he can expect after his party's convention. Obama admitted that the rate of job creation was a setback. "We know it's not good enough," he said. "We need to create more jobs faster. We need to fill the hole left by this recession faster. "We need to come out of this crisis stronger than when we went in. And there's a lot more that we can do," he told a 6,000-strong crowd in the town of Portsmouth -- in another swing state, New Hampshire. Many observers expressed disappointment with Obama's convention address late Thursday, which came after two days of well-received speeches headlined by the popular first lady Michelle Obama and former president Bill Clinton. The current US leader's address was seen as something of a rehash of his standard campaign offering, light on specifics as to how his second term would be more successful than the first in bringing unemployment down. Obama's aides, however, defended his appearance. "He did exactly what he came to do last night which is bring the choice and focus to the American people, lay out the path forward," his spokeswoman Jen Psaki told reporters traveling with the campaign. "For three days of this convention you could feel palpable enthusiasm in the convention hall," Psaki said, adding that Obama had been energized by his daughters cheering "Go get them baby" before his speech. Obama had implored Americans to give him four more years in the White House, arguing that Romney and his running mate Paul Ryan would hammer middle class family finances and return to "blustering and blundering" abroad. But he seemed to anticipate the disappointing jobs number in his speech, given in a packed sports arena, warning: "It will take more than a few years for us to solve challenges that have built up over decades." The 51-year-old president confronted the deflated hopes spawned when he was elected America's first black president in 2008 that he would lead an era of transformation and bridge the country's now-gaping partisan divide. "The election four years ago wasn't about me. It was about you. My fellow citizens -- you were the change," Obama said, citing the end of the Iraq war, more rights for gays and lesbians and creation of near universal health care. "If you turn away now -- if you buy into the cynicism that the change we fought for isn't possible -- well, change will not happen." Obama and Romney face each other in a presidential vote on November 6. Opinion polls have them running neck-and-neck, with the result likely to be decided by voters in half a dozen swing states.