The Uefa Football Board says VAR needs to become more “consistent, transparent and understandable” for players, fans and coaches.
The board, which is led by former players and elite-level coaches, met in Nyon, Switzerland on Monday.
It said that VAR should be used as a tool to help referees, and that “its interventions should not be perceived as a negative judgement on referees themselves”.
“It is clear that not everything on the pitch may be seen by the referee,” the statement added.
Uefa’s comments come after a controversial weekend for video assistant referees (VAR) in the Premier League.
Nottingham Forest have asked for the audio between officials from Sunday’s defeat at Everton be released publicly, after they criticised VAR decisions on social media.
The Premier League said it was “extremely disappointed” by Forest’s social media post but it has led to more debate surrounding the technology.
Coventry City also had a late goal ruled out for a marginal offside by VAR during their epic FA Cup semi-final against Manchester United on Sunday.
Everton manager Sean Dyche said the process is “a good thing for the outcomes of games” but added that he understood some frustrations.
“The idea of VAR was to tidy up as many decisions as possible, and statistically it’s shown that it is doing that,” said Dyche.
“I appreciate that it can get in the way of things from a supporter’s point of view, but there has to be some form of getting these decisions right.”
Wolverhampton Wanderers manager Gary O’Neil added: “The technology doesn’t seem to have cleared things up as we hoped it would.
“I’ve always thought VAR would be a big benefit to the game but maybe it hasn’t been as much of a benefit as much as I expected.”
The board also called for an improvement in player behaviour towards referees and officials, and to reduce instances of diving and time-wasting.
“The behaviour of players and coaches towards match officials in several recent instances has become a critical issue and does not contribute positively to the good image of the game,” the statement said.
“The Board concluded that it is important for coaches to set the example for their teams and for the mobbing of officials to be eliminated.”
They also called for a player-led campaign to discourage “situations of players faking injuries to gain an unfair advantage, waste time and disrupt the flow of the game”.
The meeting was chaired by Uefa football advisor and former Portugal player Luis Figo, and other representatives included Rafael Benitez, Rio Ferdinand, Jurgen Klinsmann and Patrick Vieira.
