President Obama did not rule out a terrorist connection to the mass shooting in San Bernardino on Wednesday, but said federal officials do not yet know the motive of the shooters who killed at least 14 people and wounded 17 others.

Speaking from the Oval Office, Obama also called on the nation to do some collective soul-searching, making an oblique reference to a push for stricter gun-control laws that his administration has championed, unsuccessfully, since the killing of 20 elementary school students in Newtown, Conn., three years ago.

"As the investigation moves forward, it's important for all of us, including our legislatures, to see what we can do to make sure that when an individual decides to do someone harm, we make it a little harder for them to do it. Because right now, it's too easy," Obama told reporters after meeting with his national security advisers. "We need to search ourselves as a society to make sure we take the basic steps that would make it harder, not impossible, but harder for individuals to get access to weapons."

Obama said he spoke to San Bernardino Mayor Carey Davis and thanked that city's law enforcement for its response. The FBI has taken the lead in the investigation, the president said, with assistance from local agencies.

"At this stage, we do not yet know why this terrible event occurred. We know the two individuals who were killed were equipped with weapons and appeared to have access to additional weaponry at their homes, but we don’t know why they did it," he said. "We don’t know the extent of their plans. We do not know their motivations."

Obama said that it is "possible this was terrorist-related, but we don’t know. It’s also possible this was workplace-related. Until the FBI is able to conduct a large number of interviews, until we understand the nature of the workplace relationship between the individual and his superiors, because he worked with the organization where this terrible shooting took place, until all the social media and electronic media are explored, we will not be able to answer that."

After unsuccessfully pushing Congress to approve stricter gun-control legislation in the wake of the Newtown shootings, the Obama administration has enacted small-scale changes to gun regulations through executive actions. After other mass shootings, Obama has denounced Republican opposition to the stricter laws, but the White House has not offered strategies to renew the legislative push.

"We see the prevalence of these kinds of mass shootings in the country. I think so many Americans sometimes feel as if there’s nothing we can do about that," Obama said. "We are fortunate to have an extraordinary combination of law enforcement and intelligence and military at work every single day to keep us safe, but we can’t just leave it to our professionals to deal with these kinds of horrible killings. We all have a part to play."