A new mood of unease pervaded Argentina on Friday as rattled citizens woke to the aftermath of a gun attack on their high-profile vice president that, barring a mechanical malfunction, could well have killed her.

The assailant pointed the weapon - which authorities said was loaded - at Cristina Fernandez de Kirchner outside her central Buenos Aires home from point-blank range, but it failed to discharge.

Politicians on all sides in Argentina condemned the attack, which happened amid acute political tensions as the country sinks deeper into an economic crisis driven by runaway debt and inflation.

Horacio Rodriguez Larreta, the opposition mayor of Buenos Aires city, called it "a turning point in (our) democratic history", echoing similar comments by Alberto Fernandez in an overnight address and demanding swift justice for the perpetrator.

Leaders around the region also denounced the attack.

"It was deplorable, reprehensible, but at the same time, I'd say, miraculous, because she's fine," leftist Mexican President Andres Manuel Lopez Obrador said.

A divisive figure, Fernandez de Kirchner is facing potential corruption charges linked to an alleged scheme to divert public funds while president between 2007 and 2015. A prosecutor in recent weeks called for a 12-year prison sentence against her.

She denies wrongdoing and her supporters have rallied in the streets and gathered daily outside her residence.

President Fernandez's office later called for the end of a "rhetoric of hate", while Rodriguez Larreta added: "Today, more than ever, all Argentines have to work together for peace."

The attack was streamed into households across the country via live TV images that showed the gun being pushed towards Fernandez de Kirchner's face, before she crouched down and covered her face with her hands and supporters outside her house bundled a man away.

Oscar Parrilli, a Senator with the ruling coalition close to the Vice President, told local radio she was in shock but getting by: "Luckily, she has her spirit, her temper intact."

Police arrested a suspect who they named as Fernando Andr?s Sabag Montiel, a 35-year-old Brazilian.

"Luckily the bullet didn't come out because the consequences could have been much worse," said Florencia Suera, a 22-year-old worker in Buenos Aires.

Oscar Delupi, 64, a railway worker in the capital, blamed political divisions for triggering the violence.

"It's crazy, society has already lost its temper a little, the message of hate ... is becoming more and more fierce in those weak-minded people who opt for a crazy thing like an attack," he said.