During a visit to a charter school in Harlem yesterday, President Bush called on school districts to reorganize their failing schools into charter schools and said he would expand a federal merit pay program for teachers to $200 million.

The president also touched on themes from his campaign to push Congress to reauthorize the No Child Left Behind Act, calling for a federally funded program for private school vouchers and renewal of the testing requirements that are the focus of the law.

Mr. Bush said he chose the charter school, the Harlem Village Academy, as the backdrop for his speech because of its reputation for rapidly raising the test scores of low-performing students.

Calling the founder of the school, Deborah Kenny, an “educational entrepreneur,” he pointed to Harlem Village Academy as an example of how charter schools can create competition with other public schools.

“I can’t think of a better way to get somebody’s attention that we’re tired of mediocrity than to give a parent an option,” Mr. Bush said.

He praised the school’s ability to bend rules with its nine-hour school day and Saturday classes, a jab at teachers unions that have traditionally opposed longer hours for schools.

Mr. Bush also complimented Chancellor Joel Klein, who attended the event, for his efforts to emphasize test scores and accountability in his reorganization of the city schools — which mirrors many of the No Child Left Behind measures.

Afterward Mr. Klein said he agreed with Mr. Bush that the act should be renewed, although he said it could be improved.

“I think he’s excited about the work that Mayor Bloomberg is doing,” Mr. Klein said of the president, who during his speech encouraged more cities to follow New York City’s lead in granting their mayors control of the schools.

Ms. Kenny characterized the presidential visit as a tribute to the hard work of the students, whose seventh-grade math scores are among the best in the city.

Several children at the school said they had come from low-performing public schools, and others said they had transferred to the charter school directly from parochial schools.

Some students, ready to display their training in critical thinking, had been prepared to ask the president about the Iraq war on a day when the battle over when to pull out American troops escalated between Congress and the White House.

Students were mesmerized by their important visitor, however, after Mr. Bush broke from his schedule to visit every classroom in the school — where he shook each student’s hand.

“I think it was the best day of my life,” a sixth-grader, Joseph Barber, 11, said, noting that the only other famous people he has met have been local rappers.

Of his school, he said, “They’re giving us high standards and getting us ready for college. We’ll probably graduate at the top of our classes.”

A math teacher at the school, Justin Fong, who graduated from Harvard University and described himself as a “raging liberal,” said he had taken the opportunity to challenge the president — telling him to add more money to the federal merit pay program.

“It’s not going to be enough,” he said.