Barrack Obama

"We are heartbroken by the loss of life," he said after his tour.

Mr Obama dismissed criticism that he arrived too late and praised state officials for their initial response.

The president also met the family of Alton Sterling and the families of the Baton Rouge police officers killed last month.

Mr Sterling, a black man, was killed at the hands of a white police officer in Baton Rouge.

His death, along with the police killing of Philando Castile in St Paul, Minnesota, stoked racial tensions and led to protests across the country.

"Literally" was once used, exclusively, to introduce or punctuate a point meant to be taken in literal terms. But by 2013, enough people were using it interchangeably with "metaphorically" that even leading grammar pedants threw up their hands (literally?), and the Merriam-Webster and Cambridge dictionaries expanded their definitions.

The playlists -- one curated for daytime and one for nighttime -- feature music from a wide range of singers and genres, and is available on the official White House Spotify account.

The music was "hand-selected" by the President, according to the White House, and includes classics from Aretha Franklin, Miles Davis and Prince, along with more recent artists Common, Jay Z and Wale.

The playlist also showcases artists who have performed at the White House including Janelle Monae, Sara Bareilles and Esperanza Spalding.

Mahmoud Ahmadinejad, Iran's president from 2005-2013, demanded in a letter that Obama overturn an April US Supreme Court ruling that allowed the seizure of $2 billion worth of Iranian assets to compensate victims of a 1983 terror attack.

In his entreaty, Ahmadinejad suggested Obama had failed to deliver on a promise to improve ties to Iran by allowing the court decision to stand.

It's one more historic barrier President Barack Obama has shattered.

His vehement warnings that GOP nominee Donald Trump is temperamentally and intellectually unfit for the Oval Office leave Obama standing apart from almost all of his 43 predecessors in the extent to which he has publicly expressed a hostile attitude to a potential successor.

"He's been weak, he's been ineffective," Republican candidate Mr Trump said of Mr Obama in a Fox News interview on Tuesday.

Mr Obama has questioned why Mr Trump's party hasn't disowned him.

Mr Trump has also turned on two senior figures in his own party who have publicly criticised him.

"There has to come a point at which you say: 'Enough'," Mr Obama said.

Mr Trump has been sharply criticised for attacking the parents of a fallen US soldier who spoke out against him.

He has also been condemned for backing the Russian annexation of Crimea.

Mr Obama said he had had policy differences with previous Republican presidents and candidates - but added that he had never thought they could not function as president.

Mr Obama praised Mrs Clinton at the Democratic convention in Philadelphia, as the most qualified person ever to run for the White House.

He said voters faced a choice between hope and fear, attacking "home-grown demagogue" Republican Donald Trump.

Mr Trump responded by rejecting the president's optimistic portrayal.

"Our country does not feel 'great already' to the millions of wonderful people living in poverty, violence and despair," he said on Twitter.

Side-by-side comparisons of the transcripts show the text in Trump's address following, nearly to the word, the first lady's own from the first night of the Democratic convention in Denver nearly eight years ago.

The controversy quickly overshadowed the speech. The Trump campaign signed off on the speech, according to sources. A campaign representative did not immediately respond to request for comment.

Here is Trump, on Monday:

Officers were responding to a call of shots fired when they were shot in what Baton Rouge Mayor Kip Holden described as "an ambush-style deal."

Louisiana State Police Superintendent Colonel Mike Edmonson said the gunman behind the shootings was killed and there are no suspects at large. The motive was not immediately clear.

"Baton Rouge officers at a convenience store observed the individual. He was wearing all black standing behind a beauty supply store holding a rifle," Colonel Edmonson told reporters.