President Obama told a memorial service for the five Dallas police officers killed by a sniper, that the force needs respect, and not scorn.
The President, in Texas with his predecessor George W Bush, praised the police's bravery, saying the "overwhelming majority" do their jobs "fairly and professionally".
But he admitted that people across the country were struggling with the recent shootings and that racism was an enduring problem in America.
Our Washington Correspondent Robert Moore reports:
President Obama is "deeply disturbed" by recent reports of police shootings, his spokesman has said.
Philando Castile and Alton Sterling were both shot and killed in the US by police this week.
Hillary Clinton also responded saying it was "yet another tragedy of a life cut down too soon".
President Obama is expected to issue an executive order to send US National Guard forces to Liberia to assist in the fight against Ebola, sources have told NBC News.
According to sources, no decision has been made, but the initial deployment would include eight guard and reserve engineers and logistics specialists to assist in the construction of seventeen 100-bed treatment centers for Ebola patients.
An executive would help cut through the usual official red tape and delays so that guard and reserve forces could be ordered to deploy to west Africa on a moment's notice.
While the initial force may be small in number the order would give the President the option to send further forces.
President Obama urged Americans not to be discouraged by the rocky roll-out of his health care plan, known as Obamacare, and vowed to fix any remaining glitches.
International Editor, Bill Neely reports, from Washington:
The move follows Russia's decision to grant temporary asylum to National Security Agency leaker Edward Snowden and reflects the US's frustration with Russia on issues such as missile defence and human rights.
The White House says Obama still plans to attend the Group of 20 economic summit in St. Petersburg, Russia, but has no plans to meet with Putin there one-on-one.
Obama will add a stop in Sweden to his early September travel itinerary.