Taiwan-based smartphone manufacturer Asus has announced that the release of the Android 5.0 Lollipop update for the ZenFone 4, 5 and 6 models have been delayed.

Aside from these handsets, the company also noted that the Lollipop update for the PadFone S has also been postponed.

Originally, the update was supposed to arrive sometime this month. However, Asus cited problems with the software's verification process as the primary reason behind the delay of the roll out, NDTV reported.

For the PadFone S, on the other hand, the company said it delayed the update due to the device's limited processing power.

The company made the official announcement regarding the status of the Android 5.0 Lollipop update through its ZenTalk forum page.

"Asus was scheduled to provide ZenFone 4, ZenFone 5, ZenFone 6 and PadFone S with Android L upgrade in the mid of May," the company explained. "However, Asus team has found some issues during verification."

"We decided to delay the Android L upgrade schedule in order to provide better user experience," Asus continued. "We are currently working on the related issues and will release the upgrade as soon as possible."

Asus has not yet issued a projected release date for the Android 5.0 Lollipop update. However, the company promised that it will push through with the roll out of the OS upgrade for the mentioned devices.

Currently, only the LTE version of the ZenFone 5 received the update, according to Android Headlines.

It had a file size of around 820MB and came with various improvements for the device's features. These include a new lockscreen feature, weather details and enhanced layouts for the apps and quick settings menu.

The update for the ZenFone 5 LTE also came with an upgraded Kindle, Super Note apps, Asus Webstorage, auto-star service manager, My Ocean wallpaper and improvements in the music and VOIP phone call functions.