LAUSANNE • The day after Liverpool beat Manchester City in a crunch match where VAR decisions were hotly disputed, Jurgen Klopp and other top football figures have suggested improvement is needed to the fledgling system.

Liverpool manager Klopp, his City opposite number Pep Guardiola, Real Madrid coach Zinedine Zidane, and Thomas Tuchel of Paris Saint-Germain all attended the Uefa coaches forum in Nyon on Monday, where the VAR (video assistant referee) system was a hot topic.

"It is clear it's a process where they have to keep on improving," Klopp said. "It can be improved, a lot of things have to be done by human beings and we are not 100 per cent (either).

"There is space for mistakes, nobody asks for perfection, just to have the right decision, that's all."

His comments were made a day after the marquee game of the English Premier League season - which Liverpool won 3-1 - saw a controversial VAR call after six minutes.

City could easily have had a penalty when the ball ricocheted around the Liverpool area and hit Reds defender Trent Alexander-Arnold on the arm.

Not only did VAR fail to overturn the referee's decision, but they were punished 22 seconds later when Liverpool midfielder Fabinho fired home a brilliant strike to give the Reds a 1-0 lead.

Uefa deputy general secretary Giorgio Marchetti said uniformity was needed but called for time for the promising new system to bed in.

Chief of the VAR system, Neil Swarbrick, also said that the new technology is a "work in progress".

Speaking to Sky Sports after the weekend's Premier League matches, he said: "We are in the infancy with VAR, 12 match weeks into the Premier League season, and you need to give us time to operate and utilise it.

"It's taken quite a few years for other sports to get to where they are today regarding the technology. It doesn't happen overnight."

Asked by the BBC how he would rate the use of VAR on a scale of one to 10, Swarbrick said: "I'd give us around about seven-ish. We have more decisions correct with VAR than without it."

Mike Riley, the general manager of refereeing body Professional Game Match Officials Limited, is also expected to insist that the difficulties of VAR can be worked through when he addresses the 20 Premier League clubs during their shareholders' meeting tomorrow.

REUTERS, AGENCE FRANCE-PRESSE, THE GUARDIAN