President Obama said Friday that the U.S. is considering a “limited” and “narrow” military strike against Syria given its confidence the regime hit civilians with chemical weapons.

While the president stressed he had "not made a final decision about various actions that might be taken," he said the world had "an obligation to make sure we maintain the norm against the use of chemical weapons."

"This kind of attack is a challenge to the world," Obama said. "We cannot accept a world where women and children and innocent civilians are gassed on a terrible scale."

The president said that while a "wide range of options" for possible military action was under review, the White House was not considering "any boots-on-the-ground approach."

“We're not considering any open-ended commitment,” Obama said.

"What we will do is consider options that meet the narrow concern around chemical weapons."

The president also pledged to "consult closely with Congress," and said that in addition to an unclassified report detailing the evidence that the Assad regime had used chemical weapons, administration officials would give a more detailed, classified briefing to congressional staffers in Friday afternoon.

The White House also will hold unclassified conference calls with Republican and Democratic senators on Saturday afternoon.

"Sen. McConnell believes it's important for the whole Conference to have the opportunity to communicate directly with the administration on this important issue," Senate Minority Leader Mitch McConnellAddison (Mitch) Mitchell McConnellSessions: 'We should be like Canada' in how we take in immigrants NSA spying program overcomes key Senate hurdle Overnight Finance: Lawmakers see shutdown odds rising | Trump calls for looser rules for bank loans | Consumer bureau moves to revise payday lending rule | Trump warns China on trade deficit MORE's (R-Ky.) office said late Friday in a statement.

Still, many on Capitol Hill have suggested that they would like the White House to provide more information on a possible strike.

“As we have said, if the president believes this information makes a military response imperative, it is his responsibility to explain to Congress and the American people the objectives, strategy, and legal basis for any potential action," said Brendan Buck, an aide to Speaker John BoehnerJohn Andrew BoehnerDems face hard choice for State of the Union response Even some conservatives seem open to return to earmarks Overnight Finance: Trump, lawmakers take key step to immigration deal | Trump urges Congress to bring back earmarks | Tax law poised to create windfall for states | Trump to attend Davos | Dimon walks back bitcoin criticism MORE (R-Ohio). "We — and the American people — look forward to more answers from the White House.”

Other lawmakers from both sides of the aisle have demanded that Congress vote on possible military action.

The president spoke shortly after Secretary of State John KerryJohn Forbes KerryFeehery: Oprah Dem presidential bid unlikely Dem hopefuls flock to Iowa Change in Iran will only come from its people — not the United States MORE laid out the U.S. case for a strike against Syria.

Kerry said the American intelligence community had “high confidence” that the Assad regime was responsible for a chemical weapons attack outside the Damascus suburbs. 

He pointed to an intelligence report released Friday that said 1,429 Syrians — including 426 children — had been killed in the chemical weapons attack. 

At least a dozen separate sites were targeted in the attack, according to the report, and U.S. intelligence intercepted communications “involving a senior official intimately familiar with the offensive who confirmed that chemical weapons were used by the regime.”

The president said he understood that many nations were "war wary," and said he "very much appreciate[d]" their caution himself.

"There is a certain weariness, given Afghanistan. There is a certain suspicion of any military action post-Iraq," Obama said.

But, he contended, "it’s important for us to recognize that when over a thousand people are killed, including hundreds of innocent children, through the use of a weapon that 98 or 99 percent of humanity says should not be used even in war, and there is no action, then we’re sending a signal."

The president said he was "confident that we can provide Congress all the information and get all the input they need," but at the same time warned that he did not want "the world to be paralyzed."

“A lot of people think something should be done but nobody wants to do it," he said.

Obama said the attack threatened U.S. security interests, and that allowing the attack to go unanswered would increase the probability of the future use of chemical weapons against allies like Israel or the United States itself.

The U.S. intelligence report also says the U.S. has information indicating that Assad regime forces were preparing chemical weapons in the three days before the attack.

The report said its contents came with a “high confidence assessment” that was the “strongest position that the U.S. Intelligence Community can take short of confirmation.”

A senior administration official said Friday that it was “plausible” that the death toll from the attack would rise and that he was “struck by how broad this attack was.”

“You're talking about 12 different locations,” he said. “You're talking about the use of rockets.”

Administration officials admitted that physiological samples were not included in its initial intelligence assessment, but said there was a bevy of evidence to demonstrate chemical weapons had been used. 

Kerry said that it was "common sense" that Assad's forces had deployed the weapons.

“So the primary question is really no longer what do we know,” Kerry said, “the question is what are we — we collectively in the world — going to do about it?”

The administration also said that it would brief congressional staff Friday afternoon on classified information not shared in the declassified report, following a declassified conference call with top lawmakers Thursday evening. 

Still, it remains uncertain when a strike could occur. 

U.N. inspectors are scheduled to leave Damascus on Saturday, while the president is scheduled to travel to Sweden Tuesday night, ahead of meetings at the G-20 in St. Petersburg. That could leave a window over the Labor Day holiday weekend for the president to conduct a possible strike.

On Friday, Obama said only that he would "continue to provide updates to the American people as we get more information."

—This report was originally published on Friday at 2:50 p.m. and last updated on Saturday at 10:48 a.m.