Asked earlier this week why Trump was attending the convention, given the current political tensions around gun violence, White House press secretary Sarah Huckabee Sanders said safety was a "big priority".
Gun control advocates energized by recent shootings at schools, churches and elsewhere are also focused on those elections.
He slammed countries like France and Britain, which have tough gun laws, claiming attacks and stabbings could have been prevented if only citizens were armed - at one point mimicking the assailants in the Paris Bataclan attack of November 2015 picking out their victims: "Boom!"
On Thursday, co-owner Joe Groves posted on Facebook a photo of the receipt and said, "I'm making a list of the vile, racist, moronic conversations overheard from NRA attendees eating at the restaurant".
"Griffiths said colleagues who served in the military likened their work at the London hospital to being back at Camp Bastion, the British forces base in war-torn Afghanistan", Mail Online reported.
The massacre that killed 17 people at Marjory Stoneman Douglas High School in Parkland, Florida, on February 14 seemed to mark a turning point in America's long-running gun debate, sparking a youth-led movement for tighter gun controls.
Last year, he became the first sitting president to appear in more than 30 years, declaring that the "assault" on the Second Amendment had ended.
The Parkland massacre at Marjory Stoneman Douglas High School on February 14 seemed to have marked a turning point in America's long-running gun debate, sparking a youth-led movement for tighter gun controls.
At NRA convention, Trump implores Republicans to vote, defend gun rights
Parkland survivors David Hogg and Cameron Kasky once again take to CNN to air their grievances about guns and President Donald Trump.
The president did distance himself from one of the NRA's top legislative priorities: a bill to make concealed-carry permits from any state valid nationwide.
With a limited number of characters available for that message, we simplified it to say we support "reasonable and effective gun regulations" toward that end.
The National Rifle Association's 147th annual meeting is being held in Dallas weekend.
The president will be joined at the NRA event by Vice President Mike Pence.
He left the stage to "You Can't Always Get What You Want" by The Rolling Stones.
Speaking at the annual NRA convention in Dallas, President Donald Trump reiterated his call for arming teachers in schools, insisting "98 percent of mass public shootings have occurred in places where guns are banned". But he later backpedaled on that tough talk.
The speech came as the issue of gun violence has taken on new urgency after one of the deadliest school shootings in U.S. history.