The handset maker, which is facing multiple tax cases in India, added that the proceedings in the country will not affect the timing of the deal.
Last September, Nokia had announced it would sell a substantial part of its devices and services (D&S) business, including assets in India, to Microsoft for USD 7.2 billion by March 2014.
"It now expects the transaction whereby the company will sell substantially all of its D&S business and license its patents to Microsoft to close in April 2014," Nokia said in a statement today.
Nokia and Microsoft remain committed to the transaction, it added.
The two companies have received most of the required regulatory approvals, including clearances from the European Commission and the US Department of Justice, it said.
"However, the transaction is pending approvals from certain antitrust authorities in Asia, which are still conducting their reviews," Nokia said.
The handset giant said it is confident the deal will close, resulting in the sale of substantially all of its D&S business to Microsoft.
"Nokia reiterates that ongoing tax proceedings in India have no bearing on the timing of the closing or the material deal terms of the anticipated transaction between Nokia and Microsoft," the Finnish firm said.
Microsoft said in a statement the completion of the deal will mark the first step to bring Microsoft and the Nokia D&S business together.
"We are nearing the final stages of our global regulatory approval process. To date we have received approvals from regulatory authorities in 15 markets on five continents. Currently, we are awaiting approval confirmation in the final markets," Microsoft General Counsel and Executive VP (Legal & Corporate Affairs) Brad Smith said.
This work has been progressing and the firm expects it to close next month, in April 2014, he added.
"Our acquisition will accelerate our mobile-first, cloud-first imperatives. We're looking forward to accelerating innovation and market adoption for Windows Phones and introducing the next billion customers to Microsoft services via Nokia mobile phones," Smith said.