A former US Navy veteran arrested last week for shooting two Indian engineers and an American at a bar had his first court appearance through video conference.

Adam Purinton, 51, faces one charge of first-degree murder and two charges of attempted first-degree murder in an apparent hate crime in Olathe that killed Indian engineer Srinivas Kuchibhotla and injured Alok Madasani. A third patron, 24-year-old Ian Grillot, was also wounded while trying to intervene.

Appearing in court via video conference on Monday, Purinton looked haggard and was soft-spoken. He was assigned a court-appointed attorney, and his bond remains set at $2 million. His next court date is March 9, CNN reported.

Purinton reportedly got into an argument with the victims at the Austins Bar & Grill and hurled racial slurs. He yelled "Get out of my country" and "terrorist" before shooting them. Purinton was later arrested from Applebee's restaurant in Clinton, Missouri.

In 911 calls, released by CNN-affiliate KSHB, an Applebee's bartender told the police that a man had admitted to shooting two "Iranian" people in Olathe and was looking for a place to hide.

Former Democratic presidential nominee Hillary Clinton weighed in on the matter on Twitter on Monday, calling President Donald Trump to "step up and speak out" against "threats and hate crimes".

"With threats & hate crimes on rise, we shouldn't have to tell @POTUS to do his part. He must step up & speak out," she tweeted.

Trump has yet to comment, but his Press Secretary Sean Spicer had earlier said that early reports on the Kansas shooting were "disturbing".

Kuchibhotla hailed from Hyderabad while Madasani hails from Warangal town in Telangana. They were working as aviation programme managers at Garmin, an electronics manufacturer.