MULTIMEDIA:

For an AP Interactive Graphic on the conflict in Syria, go to postandcourier.com/syria.

WASHINGTON -- Delaying what had appeared to be an imminent strike, President Barack Obama abruptly announced Saturday he will seek congressional approval before launching any military action meant to punish Syria for its alleged use of chemical weapons in an attack that killed hundreds.

With Navy ships in the Mediterranean Sea ready to strike, Obama said he had decided the United States should take military action, but also determined “our country will be better off” if Congress renders its own opinion.

At the same time, he challenged lawmakers to consider “what message will we send to a dictator” if he is allowed to killed hundreds of children with chemical weapons without suffering any retaliation.

Lawmakers will return to session on Sept. 9.

Obama spoke on the developments in Syria from the Rose Garden on Saturday.

The president’s national security team was to consult senators Saturday about Syria while House Speaker John Boehner invited House members to return early from their August break for a classified briefing as the White House readied for a possible military strike.

Vice President Joe Biden, who was scheduled to be in Delaware this weekend, stood beside Obama as he spoke at the White House. Defense Secretary Chuck Hagel and Secretary of State John Kerry also were at the White House Saturday.

Hagel, Kerry and others were to consult by phone Saturday afternoon with Senate Democrats and Republicans. Director of National Intelligence James Clapper and Obama’s national security adviser, Susan Rice, also were to participate.

The White House said the calls would be unclassified, meaning officials would be limited in what they can say.

But on Sunday, the White House planned a classified, in-person briefing for House members, according to a notice from Boehner’s office to House Republican staffers. House Democrats were planning to invite their members as well.

“This will be one of many classified briefings,” read the invitation. “However, given the numerous requests made, the speaker wanted members to have an opportunity this weekend.”

The briefing was coming a day after the administration publicly released an unclassified intelligence report concluding that Syrian President Bashar Assad’s government killed more than 1,400 last week in a chemical attack. A classified version of the assessment arrived on Capitol Hill late Friday night, the GOP notice said, and was available for all House members to review.

Obama is considering a limited military strike in response to the chemical attack, but said Friday he had not yet made a decision.