WASHINGTON — It took President Barack Obama nearly 24 hours to describe Monday’s bombings at the Boston Marathon the same way that lawmakers, experts and even his own staff did: As an act of terrorism.

That was no accident.

Obama learned in his first term that while the American people want their president to console them after a national tragedy, he should remain cautious in what he says so as not to prematurely judge a situation.

“The president’s words matter,” said Dave Carney, a longtime Republican strategist who worked in the George H.W. Bush White House. “The whole world watches and listens and dissects what he says.”

In his first statement Monday evening, three hours after the explosions, Obama praised first responders and vowed to find those responsible for the attack. But he refused to call the bombings terrorism even though lawmakers and White House aides said it was “clearly an act of terror.”

“People shouldn’t jump to conclusions before we have all the facts,” Obama said instead in a 3 minute statement at the White House.

Some conservative commentators and journalists criticized his remarks. Fox News commentator Bill O’Reilly said Obama was wrong when he called the events a tragedy.

“It was not,” O’Reilly said Monday night. “It was a vile act of violence, designed to kill innocent people, including children.”

By late Tuesday morning, Obama had issued a second brief statement that was much more pointed.

“This was a heinous and cowardly act,” the president said at the White House. “And given what we now know about what took place, the FBI is investigating it as an act of terrorism. Anytime bombs are used to target innocent civilians, it is an act of terror.”

From the start, the bombings had met most definitions of terrorism. But White House officials said Obama was careful with his words Monday in part because the information was still fluid, including the locations and number of bombs.

Terrorism experts and White House officials said that what the president uttered publicly had no bearing on the investigation of the bombings being led by the FBI.