US president Barack Obama has signed an order that starts putting into effect steep across-the-board budget cuts, after he and congressional leaders failed to find an alternative budget plan. The cuts, known as the \"sequester,\" will hack $85bn off the US federal budget between Saturday and October 1. The government says the reductions will soon result in furlough notices to government employees and will trim government spending on defense contracts and in domestic government programs. Active military personnel and anti-poverty and low-income assistance programs are largely protected from the cuts. Obama said the cuts were \"dumb and arbitrary,\" and he blamed them on the Republicans, adding that it could take a couple of weeks or a couple of months to reach a deal. Democrats want to end certain tax breaks for the wealthy to raise revenue. Republicans reject tax hikes of any kind. US president on Friday urged legislators to extend the \"continuing resolution\" that would fund most government operations beyond the current expiration date; failure to do so would shut down the government. \"I think that\'s preventable,\" Obama said of the threat of a shutdown, after meeting congressional leaders briefly at the White House.