U.S. Secretary of Education Arne Duncan said New York’s new test scores should be a benchmark for growth, not cause for concern.

U.S. Secretary of Education Arne Duncan wants New Yorkers not to worry when they see the latest round of state test scores on Wednesday.

The scores are from the first tests to measure students’ skills under the Common Core standards, and state officials have said the scores are “significantly lower” than in the past. They have warned that the scores are more in line with assessments that show a statewide college-readiness rate of about a third than with last year’s test scores, where more than half of students were deemed proficient in English and two thirds in math.

“We should absolutely not be alarmed if these test scores drop,” Duncan said today during a phone call with reporters.

Duncan has good reason to want to assuage concerns about the lower scores. While the U.S. Department of Education does not impose state learning standards, Duncan made support for shared standards a consideration in the Race to the Top funding competition, and he has defended the Common Core vigorously.

But backlash against the standards has caused several states to slow down or cancel plans to test students on mastery of them. Headlines about plummeting test scores in New York, a large state and one of the first to administer Common Core-aligned tests, could make other states wary of pressing on with the higher standards, particularly if officials there fear repercussions from Washington, D.C.

“New York is far from unique as they go through this transition,” Duncan said.

Citing Tennessee as an example, he said short-term declines are likely to pay off with long-term dividends. Test scores in Tennessee fell sharply in 2010 when the state adopted higher standards, but since then, they have inched back upwards as students and teachers rise to the higher standards, Duncan said.

“They’re starting to see great results,” he said. “Last year in Tennessee students made the biggest single-year jump in achievement ever recorded in the state.”

New York State also raised its proficiency cutoff in 2010, and test scores fell sharply. They inched up again in the two following years.

Washington, D.C., has also begun to adjust to higher standards, Duncan said, while State Education Commissioner John King noted during the phone call that Massachusetts is now seen as the strongest-performing state more than a decade years after the state adopted higher standards. None of the other states and districts have yet tested students on the Common Core standards.

Duncan and King were joined by New York City Department of Education Chief Academic Officer Shael Polakow-Suransky on the call with reporters.

While city officials say they support the higher standards, the new scores represent a threat to Mayor Bloomberg’s education legacy, and officials here are aggressively working to frame their release.

Convening reporters at the Department of Education’s headquarters this afternoon, Chancellor Dennis Walcott made another pitch for how to explain the lower scores.

“I want to be very clear to the parents. It doesn’t mean that your child is doing any worse,” he said. “It just means that your child is now being measured to a higher standard and our goal is to make sure the child reaches the higher standard.”

Duncan suggested that local anxiety about the scores did not cause him to weigh in. ”I’ve talked to many many states,” he said. “This is not truly exceptional at all.”