If Congress fails to act on President Obama’s call to rewrite the No Child Left Behind law by the start of next school year, Education Secretary Arne Duncan said he will take steps to ease some of its most punitive provisions for states that are making strides in improving schools.

“We are hearing a tremendous amount of frustration across the country,” Duncan said in a conference call Friday with reporters. “We are not going to sit back here and do nothing.” He spoke on the condition that his remarks would not be made public until Sunday.

Many teachers and state leaders have long protested that the 2002 law is too punitive, too strict and fundamentally unrealistic. The law sets a goal for all students to show proficiency in reading and math by 2014.

Duncan predicted in March that by next year, the vast majority of public schools would miss their ever-increasing target pass rates on standardized tests in those subjects. Schools that fall short are labeled as failing to make “adequate” progress and face possible sanctions, such as requirements to offer tutoring or allow students to transfer. In the worst cases, they may face mandatory administrative overhauls.

Already, hundreds of schools in the Washington region have fallen short of the federal targets, sometimes because of a handful of struggling students. The failure rate in 2009 was 23 percent in Maryland, 28 percent in Virginia and 75 percent in the District, according to an analysis by the Washington-based Center on Education Policy.

Duncan said the law also is inhibiting states that are trying to make lasting changes to their schools. He plans to develop a systematic approach to granting waivers that would encourage such improvements. Although he did not offer details on what the government would look for, he said any framework for decisions would reflect the Obama administration’s agenda, which includes adopting more rigorous standards, encouraging charter schools, offering tests that measure how much students learn and overhauling teacher evaluations.

Expectations for student performance would continue to be high, he said, but states would have more flexibility to make changes. “This is not about giving states a break,” Duncan said.

Congress has been deadlocked over proposals to change the law, while debating such issues as the federal role in education and how teachers should be evaluated. Some observers say the impasse could continue for the next few years.

Sen. Tom Harkin (D-Iowa), chairman of the Senate’s education committee, called Duncan’s contingency plan “premature” and said lawmakers are making “good progress” toward introducing a comprehensive bill. “The best way to fix the problems in existing law is to pass a better one,” he said in a statement.

Harkin said in March that he would introduce a bipartisan bill by Easter, then later moved that deadline to Memorial Day. A new timeline has not been set.

A spokeswoman for Rep. John Kline (R-Minn.), chairman of the House education committee, said that Kline “remains concerned about any initiative that would allow the secretary to pick winners and losers in the nation’s education system.”

For most schools across the country, any sign of relief would be welcome, said Reginald Felton, director of federal relations at the National School Boards Association. Some of the law’s sanctions have placed a heavy burden on cash-strapped school districts without proving to be effective, Felton said. He called Duncan’s assertion of the power to take administrative action “a move in the right direction.”