WASHINGTON  President Obama and Congress are ending the year as they began it, at work on an economic stimulus package of tax cuts and spending, with the latest effort likely to raise the total cost of antirecession measures to the $1 trillion level that some economists had urged last winter.

In a speech on Tuesday, Mr. Obama outlined proposals intended to promote job creation. They included incentives for small businesses to hire more workers, additional money to build roads and other construction projects, and rebates for homeowners who invest in energy-saving weatherizing improvements.

Mr. Obama did not put a price on the proposals, which would add to the $787 billion that Congress allocated last winter to revive the economy. But he said the cost could be offset by some of the $200 billion in lower-than-expected spending on the bailout of financial institutions.

More than half of the original stimulus package remains in the pipeline, with many road building and construction projects beginning in 2010. But Mr. Obama, in his address at the Brookings Institution, a policy research organization, said further stimulus was needed to spur employers to hire and bring down a jobless rate that stands at 10 percent.