ST. LOUIS — The federal government has frozen some aid to tornado- and flood-ravaged Missouri and the South to focus on immediate help for victims of Hurricane Irene, disappointing residents and officials who said Monday they still need help.

Federal Emergency Management Agency spokesman Bob Josephson said FEMA’s Disaster Relief Fund is running low — down to between $800 million and $1 billion. When that happens, the agency focuses on immediate response, rather than long-term rebuilding. It also needs to ensure there’s enough money to respond to any other disasters that might occur this year, he said.

The shift drew criticism from Missouri’s senators, who promised to push to get full funding restored for Joplin, where a May 22 tornado killed 160 people and damaged about 7,500 homes, and other parts of the country hit by disasters earlier this year.

A little-noticed provision in the recently-passed debt limit and budget deal permits Congress to pass several billion dollars in additional FEMA disaster aid, but the White House has yet to ask for more money.