Details have emerged that before shooting the two Indian engineers- Srinivas Kuchibhotla and Alok Madasani- in a Kansas city (US) bar, the shooter held a brief conversation with them inquiring about their visas.

In a phone interview to the New York Times, Madasani described the remarks made Wednesday by the accused, Adam Purinton, a US Navy veteran, sitting near them at the restaurant.

"He asked us what visa are we currently on and whether we are staying here illegally," Madasani said. (Both men were educated in the United States and were working here legally.)

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"We didn't react. People do stupid things all the time. This guy took it to the next level," said Madasani.

Other customers present at the time of the incident said that Purinton was tossing ethnic slurs at the two men and suggesting they did not belong in the United States (US).

Madasani said he went in to get a manager, and by the time he returned to the patio, the man was being escorted out. But a short time later, he came back in a rage and fired at the two men, the authorities said.

Kuchibhotla was killed, and Madasani was wounded, along with a 24-year-old man who had tried to apprehend the gunman, who fled.

Purinton, 51, was later extradited to Kansas from Missouri on Friday, and charged with premeditated first-degree murder and two counts of attempted premeditated first-degree murder.

The possible hate crime has raised new alarms about a climate of hostility toward foreigners in the United States, where President Donald Trump has made clamping down on immigration a central plank of his "America first" agenda.

Meanwhile, the White House strongly rejected the notion that there might be any connection between the shooting and the new administration's sharp language about immigration.

Madasani, who has been released from the hospital, said he was recovering physically and mentally. "I'm definitely doing much better, but it's not over yet," he said.