The latest tax follows the introduction of a regional fuel tax, which saw the price of fuel jump 11.5 cents in Auckland earlier this year.
He said the country had been witnessing record petrol prices and Gull was determined to offer some breathing space wherever possible.
"The fuel excise tax is inevitable, and we will be putting up our prices but that can wait until [Wednesday]," Mehta told the Herald on Friday.
Recently, there were long queues outside Gull service stations when the company decided to drop its fuel price 12 cents to $2.05 a litre for 91 between 7am on Thursday September 20 and 12pm on Friday September 21.
Thereafter, Gull increased the price of 91 up to its current average of $2.17 per litre.
The bumper petrol prices and the already high cost of living are making it difficult for some New Zealand families, National Party leader Simon Bridges said.
"New Zealanders are already paying record prices for petrol, with the national fuel price at $2.44 a litre for 91, around half of which is already tax. That follows the Government adding another 4 cents per litre of tax on petrol overnight.
"And that's just the first of three 4 cent hikes plus the likelihood Auckland's 11.5 cents per litre regional fuel tax will soon be rolled out around the rest of the country.
"Under this Government petrol prices have increased by 38 cents, meaning it now costs Kiwis an extra $20 each time they fill up their cars.
"On top of this, ACC this week proposed a 12.1 per cent hike in the average motor vehicle levy for road users, including almost 2 cents a litre increase for petrol," he said.
On Thursday, ACC proposed increasing the road user levy which would increase the price of petrol by two cents a litre.
That's on top of today's introduction of nationwide petrol excise duty of 3.5 cents a litre.
The levy was put forward by ACC to help pay for the increasing costs associated with the higher number of road accidents across the country.
The Opposition has called on the Government to immediately rule out implementing the levy, but ACC Minister Iain Lees-Galloway was waiting until ACC's four-week public consultation period has ended before making his recommendation to Cabinet.
But speaking to media, Lees-Galloway did not sound keen on slapping another tax on Kiwis at the pump.
"I can assure everyone that this Government is very well aware of the cost pressure New Zealanders face – we're able to take that into account when we make our decision about ACC levies and we will."
National's Transport Spokesman Jami-Lee Ross said the levy is yet another tax that is being proposed to hit motorists at "literally the worst possible time".
"We're already seeing stories of the record high price of fuel taking food off the table for families and putting the pinch on household budgets across New Zealand."