Congress appears headed for a short-term extension of a popular nutrition law that provides food aid for millions of low-income children and pregnant women.

An extension would buy lawmakers time to reauthorize the law, which expires Sept. 30. The federal government spends about $15 billion a year on the programs operated under the law.

Some lawmakers and nutrition advocates want to strengthen the existing law. Despite a history of bipartisan support, the legislation has been pushed to the sidelines as Congress focused on economic recovery, health care reform, food safety and climate change.

“There will probably be some type of extension done to keep it at its current state,” said Cathy Schuchart, child nutrition and policy staff vice president for the School Nutrition Association. “I think it’s going to be very difficult — since we haven’t even seen a [committee] bill — for them to get something done in 30 days.”

In 2004, the Senate and House renewed the law by voice vote. That action came after lawmakers gave themselves more time to work with a short-term extension.

But Jim Weill, president of the Food Research and Action Center, said simply renewing the current law is insufficient. He said the “recession has underscored both the many strengths and the still remaining weaknesses of the nation’s child nutrition programs in responding to child hunger and family food insecurity” and that lawmakers need to “move as quickly as possible — this year or early next year — to strengthen the programs.”

One challenge facing Congress is finding budget offsets to provide the $1 billion a year in additional money for child nutrition programs sought by President Obama. The money is subject to pay-as-you-go rules.