An emotional President Obama took the gloves off against Donald Trump in the wake of the Orlando shootings on 12 June, calling the candidate un-American and dangerous in a speech delivered on Tuesday (14 June) before members of the US Department of The Treasury.

Obama let loose after Trump insinuated that a mysterious link exists between the president and terrorism, telling Fox News: "There is something going on." Trump has often implied that Obama is Muslim.

Trump has also repeatedly bashed the president for his failure to use the exact phrase "radical Islamic terrorism."

Obama said that Trump's call for a ban on Muslim immigrants — plus any immigrants from world terror hotspots — and the wedge he drives between Americans makes the nation more dangerous, noted NBC.

"Where does this stop?" Obama asked in remarks in a speech delivered before members of the Treasury Department. "Are we going to start treating all Muslim Americans differently? Place them under special surveillance? Discriminate against them because of their faith? That's not the America we want. It doesn't reflect our ideals."

Obama warned that if the US abandons its core values of tolerance, "we would not only make it a lot easier to radicalise people here and around the world, but we would have betrayed the very things we are trying to protect."

He hammered Trump over his "dangerous" mindset and "loose talk and sloppiness," and indicated that Trump's remarks were driving Muslims, who might be vulnerable to radicalisation, into the arms of the Islamic State (Isis).

Orlando Shooting
U.S. President Barack Obama speaks about the worst mass shooting in U.S. history that took place in Orlando, Florida, at the White House in Washington, U.S., June 12, 2016. Reuters

"If we fall into the trap of painting all Muslims with a broad brush we are doing the terrorists' work for them," Obama said. And he finally let Trump have a sucker punch, over the candidate's insistence that Obama use the phrase "radical Islamic terrorism."

"What exactly would using this label accomplish? What exactly would it change?" Obama asked. "Would it make ISIL less committed to try and kill Americans?" he continued, using a different acronym for ISIS.

"Would it bring in more allies? Is there a military strategy that is served by this? The answer is none of the above," he said. "Calling a threat by a different name does not make it go away."

He added: "There's no magic to the phrase radical Islam. It's a political talking point. The reason I am careful has nothing to do with political correctness and everything to do with defeating extremism."

Orlando shooting
President Obama: He's not happy. Alex Wong/ Getty Images

Trump blasted back during a speech in North Carolina, complaining that Obama was "angrier at me" than at the Orlando shooter. He also issued a statement to Associated Press that the president "continues to prioritise our enemy over our allies, and for that matter, the American people."

Trump was roundly criticised by many after he accepted "congratulations" for being "right" about terrorism in the wake of the Orland massacre. Many in the GOP leadership have remained silent on his remarks — or criticised them, reports NBC.

"I'm not hopeful right now," said Arizona's Republican Senator Jeff Flake, who has refused to endorse Trump. Trump's "ill-informed, ill-conceived ban on Muslims" is damaging the Republican Party, he said.

Trump's statement after the Orlando massacre "wasn't the kind of response that I would expect when 50 people have perished," said Tennessee Republican Senator Bob Corker. "I've offered words of public encouragement [to Trump] in important times and continue to be discouraged by the results."