WASHINGTON — President Barack Obama on Thursday will free 10 states from the strict and sweeping requirements of the No Child Left Behind law, giving leeway to states that promise to improve how they prepare and evaluate students, The Associated Press has learned.

The first 10 states to receive the waivers are Colorado, Florida, Georgia, Indiana, Kentucky, Massachusetts, Minnesota, New Jersey, Oklahoma and Tennessee. The only state that applied for the flexibility and did not get it, New Mexico, is working with the administration to get approval, a White House official told the AP.

The official spoke on condition of anonymity because the states had not yet been announced. A total of 28 other states, the District of Columbia and Puerto Rico have signaled that they, too, plan to seek waivers — a sign of just how vast the law’s burdens have become as a big deadline nears.

No Child Left Behind requires all students to be proficient in reading and math by 2014. Obama’s action strips away that fundamental requirement for those approved for flexibility, provided they offer a viable plan instead. Under the deal, the states must show they will prepare children for college and careers, set new targets for improving achievement among all students, reward the best performing schools and focus help on the ones doing the worst.