Obama says debate on guns 'needs to change'

President Barack Obama traveled to grief-stricken Orlando Thursday, meeting loved ones devastated by a shooting rampage and using his bully pulpit to demand that the Republican-controlled Congress pass gun control.

Following the worst mass shooting in modern US history at the Pulse nightclub last Sunday, Obama said lawmakers need to "rise to the moment and do the right thing."

He added that the tone of the country's hyper-partisan debate on firearms "needs to change."

"The motives of this killer may have been different than the mass shooters in Aurora or Newtown," Obama said, listing two in the litany of mass shootings that have marked his presidency.

"But the instruments of death were so similar."

"And now another 49 innocent people are dead. Another 53 are injured. Some are still fighting for their lives. Some will have wounds that will last a lifetime."

Obama insisted that while the military would tackle the Islamic State group, Al Qaeda and other extremist groups in their hideouts and intelligence services would work to disrupt their networks, the government could not catch every "deranged person."

"But we can do something about the amount of damage that they do," he said.

"Unfortunately our politics have conspired to make it as easy as possible for a terrorist or just a disturbed individual like those in Aurora and Newtown to buy extraordinarily powerful weapons and they can do so legally."

The Republican-controlled Congress has steadfastly refused to pass any gun legislation, saying to do so would infringe on gun owners' constitutional rights.

In a rare symbolic show of bipartisanship, Obama arrived with Republican one-time presidential hopeful Marco Rubio and was greeted on the tarmac by Republican Florida governor Rick Scott and Vice President Joe Biden.

Obama and Biden also met emergency medical crews and hospital staff who labored to save lives in the chaotic hours after the massacre by gunman Omar Mateen, a 29-year-old Muslim American of Afghan descent.

Mateen was killed in a police raid, but how he came to possess a special forces assault rifle remains deeply contentious.

Mateen pledged allegiance to the leader of the Islamic State group in a 911 call during the attack.

The IS group then claimed responsibility for the shooting, and FBI agents believe that Mateen was radicalized by following extremist propaganda online.

That has prompted Republicans to call for tougher counterterrorism measures and for the Obama administration to do more to fight the Islamic State group.

Senator John McCain went as far as to suggest that Obama's policies in the Middle East were directly responsible for the shooting.