COLUMBIA, Mo. -- The No Child Left Behind law is "sufficiently funded," Education Secretary Rod Paige said Monday, replying to criticism that the law passes along billions in costs to states and local school districts.

"There is no unfunded mandate as far as the No Child Left Behind Act," Paige said during a forum hosted by Rep. Kenny Hulshof, R-Mo., at Columbia's Rock Bridge High School.

The bipartisan National Conference of State Legislatures estimated on March 10 that No Child Left Behind will cost states $9.6 billion more in the coming budget than is provided by Washington.

In an interview with The Associated Press after the forum, Paige, a former chief of Houston's public schools, said he acknowledges that schools "are inside a financial kind of crunch and schools are challenged."

"I was simply making a point -- don't confuse what is required by the act by all the other places where you need money. I know you need money in these other places. I was a school superintendent, I know you need money," he said.

Local superintendents say the federal funding provided for No Child Left Behind is insufficient.

"I'd like to know what money we're getting that is funding it," said Diann Bradshaw-Ulmer, superintendent of the Scott City School District.

Bradshaw-Ulmer said her district has seen a slight increase in federal Title I money, but that funding is earmarked specifically for services to low-income students.

Title I does not offset the costs incurred because of No Child Left Behind, Bradshaw-Ulmer said, such as additional professional development for teachers or rewriting the school's curriculum to meet the federal law's standards.

Dr. Rita Fisher, assistant superintendent in the Jackson School District, said No Child Left Behind's testing requirements have been an added cost.

"I think higher stakes testing and the level of accountability is putting a strain on school districts at a time when we're already feeling a crunch financially," Fisher said. "In our district, I see less money and higher class sizes."

Staff writer Callie Clark contributed to this report.