WASHINGTON — Barely into the new school year, President Barack Obama issued a tough-love message to students and teachers on Monday: Their year in the classroom should be longer, and poorly performing teachers should get out.

American students are falling behind their foreign counterparts, especially in math and science, and that’s got to change, Obama said. Seeking to revive a sense of urgency that education reform may have lost amid the recession’s focus on the economy, Obama declared that the future of the country is at stake.

"Whether jobs are created here, high-end jobs that support families and support the future of the American people, is going to depend on whether or not we can do something about these schools," the president said in an interview on NBC’s "Today" show.

U.S. schools through high school offer an average of 180 instruction days per year, according to the Education Commission of the States, compared to an average of 197 days for lower grades and 196 days for upper grades in countries with the best student achievement levels, including Japan, South Korea, Germany and New Zealand.

"That month makes a difference," the president said. "It means that kids are losing a lot of what they learn during the school year during the summer. It’s especially severe for poorer kids who may not see as many books in the house during the summers, aren’t getting as many educational opportunities."

Obama said teachers and their profession should be more highly honored — as in China and some other countries, he said — and he said he wanted to work with the teachers’ unions. But he also said that unions should not defend a status quo in which one-third of children are dropping out. He challenged them not to be resistant to change.

And the president endorsed the firing of teachers who, once given the chance and the help to improve, are still falling short.

"We have got to identify teachers who are doing well. Teachers who are not doing well, we have got to give them the support and the training to do well. And if some teachers aren’t doing a good job, they’ve got to go," Obama said.

They’re goals the president has articulated in the past, but his ability to see them realized is limited. States set the minimum length of school years, and although there’s experimentation in some places, there’s not been wholesale change since Obama issued the same challenge for more classroom time at the start of the past school year.

One issue is money, and although the president said that lengthening school years would be "money well spent," that doesn’t mean cash-strapped states and districts can afford it.

"It comes down to the old bugaboo, resources. It costs money to keep kids in school," said Mayor Scott Smith of Mesa, Ariz. "Everyone believes we can achieve greater things if we have a longer school year. The question is how do you pay for it."

One model is Massachusetts, where the state issues grants to districts that set out clear plans on how they would use the money to constructively lengthen instructional class time, said Kathy Christie, chief of staff at the Education Commission of the States. Obama’s Education Department already is using competitions among states for curriculum grant money through its "Race to the Top" initiative.

"The federal carrots of additional money would help more states do it or schools do it in states where they don’t have a state grant process," Christie said.

But the federal budget is hard-up, too. And while many educators believe students would benefit from more quality learning time, the idea is not universally popular.

In Kansas, sporadic efforts by local districts to extend the school year at even a few schools have been met by parental resistance, said state education commissioner Diane DeBacker.

"It’s been tried," she said, describing one instance of a Topeka-area elementary school that scrapped year-round schooling after just one year. "The community was just not ready for kids to be in school all summer long. Kids wanted to go swimming. Their families wanted to go on vacation."

Teachers’ unions say they’re open to the discussion of longer classroom time, but they also say that pay needs to be part of the conversation. As for Obama’s call for ousting underperforming teachers, National Education Association President Dennis Van Roekel said unions weren’t the main stumbling block there, as many education reformers assert.

"No one wants an incompetent teacher in the classroom," Van Roekel said. "It’s in the hiring, and in those first three to five years no teacher has the right to due process."

___

Associated Press Writers Ben Feller and Julie Pace in Washington, Karen Matthews in New York, Donna Gordon Blankinship in Seattle and Alan C. Zagier in Columbia, Mo., contributed to this report.