President Obama says the country can't protect police from every danger, but Americans can work harder to heal rifts with communities they serve.

With controversy surrounding a string of deaths nationwide involving law enforcement, Obama is offering his gratitude for the service of officers during an annual memorial service for fallen police on the West Lawn of the U.S. Capitol.

He says America holds police officers up as heroes "because that's what they are."

He's also calling in Friday's appearance on fellow citizens to make sure that police have the support and resources they need and to combat the poverty that plagues too many communities where they serve.

Obama says America owes that to all who wear the badge with honor and to the officers who gave their lives.