"The president's whole message is about personal responsibility and challenging students to take their education very, very seriously," said Education Secretary Arne Duncan, who explained that Obama simply wanted to encourage the country's youth to do their best.
"We have some very important goals for the country. We want to see more high-performing schools, we want to see more students improving their academic achievement, we want to see more students going to college, and succeeding and graduating," Duncan told the CBS News program "Face the Nation."
"None of those things happens -- it's impossible -- if students are not working hard every single day," the nation's chief education official said.
He also said he was amazed that the last time a president made such a speech to US students was in 1991.
"The real question I have is, why has it been 18 years since a president has addressed our nation's youth?"
His comments came in response to conservative criticism that the president's speech was an attempt at "indoctrination" of kids and after droves of parents phoned school boards to complain.
Critics have suggested that the aim of the speech was to recruit US kids to the liberal cause and brainwash them with socialism.
Their ire was sparked in part by a "Menu of Classroom Activities" which the Department of Education sent to schools around the country when the speech was announced. One of the activities suggested that school children write about "how they could help the president."
"That's Obama-centric. It's not focused on education but on the worship of Barack Obama," Michael Leahy, spokesman for the conservative grassroots Nationwide Tea Party Coalition told AFP.
"This is indoctrination, pure and simple, into the cult of Barack Obama, and we are opposed to that," he said.
Jim Greer, chairman of the Republican Party of Florida, raged that "Pied Piper Obama" was going "into the American classroom" to spread socialist ideology.
Some school districts took the decision not to air the speech, others said they will leave the decision to teachers and school principals, and some offered opt-outs for children whose parents do not want them to see or hear the address.
A middle school in the Washington suburb of Bethesda sent an email to parents explaining that students would be provided "the opportunity to view the speech... at the end of the day."
It added that "students will be allowed to opt out by bringing a note from a parent."
One official whose school district is leaving the decision on airing the speech to school principals and teachers, said parents had inundated the school board with calls complaining about the speech, but added that they were "jumping the gun."
"What they think is going to be in the speech is very different to the outline of the speech I've seen. A lot of people are making some very large assumptions about what Obama is going to say," said the official who asked not to be identified.
Cynthia Farris Sprock, a California mother of a high school student who describes herself as "usually conservative," said the hullabaloo was "more right-wing hysteria."
"I think most kids and rational adults would agree that listening to presidential speeches is a valid thing to do, even if it's just for discussion purposes," she said.
"And since when do we assume that everyone who listens to a presidential speech agrees with everything being said?"
To help calm fears, the White House has said the text will be published on Monday, a day before Obama delivers it, to allow everyone to see its focus will be to encourage America's children to stay in school.
And Duncan's Department of Education has re-worded the contentious line in the classroom activities list suggesting children write about how they can help Obama.
It now suggests that students "write letters to themselves about how they can achieve their short-term and long-term education goals."
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