US businesses cranked up hiring in January, pulling down the unemployment rate for a fifth straight month amid signs of a stronger recovery brewing in the world\'s largest economy. The Labor Department\'s keenly awaited jobs report blew past expectations, providing a shot of welcome good news for President Barack Obama\'s reelection bid. The economy added 243,000 net new jobs in broad-based gains, while the unemployment rate fell from 8.5 percent in December to 8.3 percent, the lowest rate since February 2009. US stocks rallied sharply on the news, up more than 1.0 percent in afternoon trade in New York. But analysts cautioned against reading too much into one month\'s numbers. In echoes of Federal Reserve chairman Ben Bernanke\'s concerns, they warned that the ailing labor market has a long, slow road to health and faces potential setbacks, not least from a negative impact from Europe\'s debt crisis. Moody\'s Analytics analyst Sophia Koropeckyj pointed to a number of challenges, including weak fiscal conditions, an expected increase in home foreclosures, the European public debt crisis, and slowing global growth. \"However, the very strong start to the year may also indicate that the US economy is more resistant to these threats than we believe,\" she said. With jobs at the top of the campaign agenda ahead of the November elections, Obama seized on the data to urge opposition Republican lawmakers not to \"muck up\" the momentum and support an extension of a payroll tax cut for the rest of the year. \"So I want to send a clear message to Congress: Do not slow down the recovery that we\'re on. Don\'t muck it up. Keep it moving in the right direction.\" Leading Republican presidential candidate Mitt Romney welcomed the decline in unemployment but accused Obama of preventing \"a true economic recovery.\" \"Last week, we learned that the economy grew only 1.7 percent in 2011, the slowest growth in a non-recession year since the end of World War II,\" Romney said. \"We can do better,\" Romney said. The numbers were much stronger than analysts\' expectations. The average estimate was that the jobless rate held steady and job creation would slow, to 155,000 jobs. But job creation in January was the strongest since April 2011, and was well up from December\'s 203,000 figure. Businesses put 257,000 jobs on their payrolls, while government layoffs, which had limited net jobs generation over the past two years, slowed to 14,000. The jobs gains were broad-based, in professional and business services, leisure and hospitality, and manufacturing sectors, while the information, finance and clothing retailer sectors shed jobs. The average workweek in the private sector in January was unchanged from December but wages rose 0.2 percent. \"The January figures were helped by exceptionally mild winter weather, but that does not remove the shine from a very encouraging report,\" said Nigel Gault at IHS Global Insight. Analysts cautioned that January job numbers are notorious for future revisions, but pointed to other recent positive indicators in January, including increases in auto sales and in closely watched surveys of manufacturing and services. The ISM services sector index released Friday showed solid growth in new orders and jobs.