Football's law-makers say the video assistant referee system should not be "too forensic" when it comes to offsides - and should only be used to reverse "clear and obvious" errors.
Five goals in the Premier League were ruled out at the weekend for marginal offsides, leading some managers and players to criticise VAR.
Lukas Brud, general secretary of the International Football Association Board, said: "With VAR we see some things that are going in a direction that we may need to re-adjust."
He said the body would reissue guidance on VAR's use after its annual general meeting in February.
"If you spend multiple minutes trying to identify whether it is offside or not, then it's not clear and obvious and the original decision should stand," he said.
He added: "What we really need to stress is that 'clear and obvious' applies to every single situation that is being reviewed by the VAR or the referee.
"In theory, 1mm offside is offside, but if a decision is taken that a player is not offside and the VAR is trying to identify through looking at five, six, seven, 10, 12 cameras whether or not it was offside, then the original decision should stand.
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"This is the problem. People are trying to be too forensic. We are not looking to make a better decision, we are trying to get rid of the clear and obvious mistakes.
"If video evidence shows that a player was in an offside position, he was offside full stop. If it's not obvious, then the decision cannot be changed, you stay with the original decision.
"We will be communicating to all competitions that are using VAR some updates in the coming weeks, because we are observing some developments that are not particularly the way they should be."
'Something has to change'
Meanwhile, former top-flight referee Mark Halsey told BBC Radio 5 Live that the Premier League needs to change its use of VAR next season.
"You cannot change it halfway through a season but something has to change at the end of the season and it has to involve players and fans," he said. "VAR is here to stay and, used correctly, it shouldn't be a problem."
Halsey, who officiated in the Premier League from 1999 to 2013, said referees' body PGMOL was "not using it correctly" compared with other countries that have VAR.
"Everywhere else is going to the pitchside monitor and that is not happening [here]," he said.
Marginal offsides are causing particular consternation, with Sheffield United boss Chris Wilder saying VAR was "not helping the game".
Some fans have been singing "it's not football any more" at matches.
Another former Premier League official, Dermot Gallagher, told BBC Radio 5 Live the recent examples had shown "how tight the margins are".
"The technology will get better and the operatives will get better. We've got to allow it a bit of wriggle room. It was never going to be perfect," he said.
"It's frustrating. I think people will get more used to it, people will tinker with the product a little bit and say, 'If we do this it will make it better', and I think it's a combination and with that right combination we will eventually get the right cocktail."
Sheffield United suffer most from VAR calls
Norwich, Brighton, Crystal Palace, Wolves and Sheffield United all had goals chalked off for offside via VAR at the weekend, with the Blades now having had five goals ruled out for offside - the most of any Premier League team.
They have had a total of seven VAR decisions go against them, more than any other top-flight team.
Halsey said: "We've seen 21 or 22 goals ruled out through offside, but some of them have got to be given as goals because fans are paying a lot of money to watch.
"We don't want to see them ruled out for a toenail or hair. They are goals, and if it's taking so long to judge then you go with the on-field referee.
"We know technology isn't 100%, so where are they drawing these lines? They've been consistent, but it doesn't make it right."
Wolves had two VAR decisions go against them in their 1-0 defeat by Liverpool on Sunday, when VAR ruled that the league leaders' goal should stand and when they also had Neto's equaliser ruled out for a marginal offside.
Captain Conor Coady said the system was "not working" and was "confusing" for players, while Manchester City boss Pep Guardiola said VAR was "a big mess", despite Sheffield United being disadvantaged against his side.
Guardiola said: "Hopefully next season it can do better."
Wilder added: "Yet again we had another goal disallowed by VAR. That's about eight or nine over the weekend, this is not a situation helping the game."
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|Stats via Opta as of 30 December 2019|