Tech giant Apple has agreed to begin paying more than $15 billion in back taxes to Ireland next year -- while appealing a European Union decision, officials said Monday.

Irish finance chief Paschal Donohoe said Apple will start paying the money into an escrow fund during the first quarter of 2018.

Last year, the European Union determined that a deal between Ireland and Apple for tax incentives was illegal and ordered Dublin to recover uncollected taxes for the years between 1991 and 2007.

Ireland had held off collecting the money and the matter was appealed to the EU Court of Justice.

Irish officials have said the EU misinterpreted some laws and overstepped its authority. Apple argued the amount owed had "fundamental errors" with most profits.

While the decision is being appealed, the money will be held in an escrow fund. Apple has said it wanted to negotiate the interest rate of the escrow fund.

"We have a dedicated team working diligently and expeditiously with Ireland on the process the European Commission has mandated," Apple said in a statement. "We remain confident the General Court of the EU will overturn the Commission's decision once it has reviewed all the evidence."