BELO HORIZONTE • Argentina's Lionel Messi and Sergio Aguero lashed out at the officiating after their 2-0 Copa America semi-final loss to Brazil on Tuesday and questioned why video technology was not consulted in two penalty appeals that were waved away.

The video assistant referee (VAR) system has been used heavily at the tournament and has had a huge impact, ruling out three Uruguay goals in their quarter-final exit to Peru as well as two strikes for Chile in their last-eight shoot-out win over Colombia.

The group stage also saw many goals chalked off after lengthy stoppages for reviews, while several penalties were awarded even when there had been no appeals for a foul.

On Tuesday, however, VAR was conspicuous by its absence and Messi, not known for verbal outbursts, was furious it was not used.

"Referees gave so many stupid fouls in this Copa but today VAR wasn't consulted once," he said. "This should be looked into and I hope (South American football governing body) Conmebol do something with these referees who unbalance the pitch by favouring a team.

"The truth is we're angry because we played very well, and for it to end like this makes us sad."

Aguero appeared to be tripped by Dani Alves in the second half but no foul was given and Brazil immediately launched a counter-attack which saw Roberto Firmino adding to the 19th-minute Gabriel Jesus goal.

Later, defender Nicolas Otamendi went to ground after tangling with Arthur at a corner but Argentina's appeals were again futile.

"They told us that VAR would be like a fifth referee but when things turn out like this I'd rather it wasn't there," said Aguero.

"I was running and Alves stopped me with his foot, it was clear."

Argentina, whose last trophy was the 1993 Copa, again left empty-handed after failing to beat their arch-rivals in a major competitive match since 2005.

It also extended Messi's long wait for a trophy.

Having tasted defeat in four finals, three of them coming between 2014 and 2016, this exit marks the ninth tournament Messi has failed to earn a winners' medal.

But it was not for the lack of trying on Tuesday.

Messi, uncharacteristically sluggish in the previous four games, was at the centre of most of their best moves as they bossed the shot count 14-4, particularly during a pulsating second half when he hit the post.

It was an improvement but more was expected of Argentina's all-time top scorer (68 goals), who has won 29 trophies with Barcelona but has only a 2008 Olympic gold medal to show for Argentina.

The 32-year-old suggested he was still committed to the Argentina cause.

"Something new is on the horizon," he said. "If I can still help in any way, I will continue to do so. I feel good in this group. They have a future and great foundations."

REUTERS, AGENCE FRANCE-PRESSE