Zayn Malik emotional on Twitter

Zayn Malik has "nothing left to give".

The 21-year-old singer makes up one fifth of boyband One Direction along with Harry Styles, Louis Tomlinson, Liam Payne and Niall Horan.

He's engaged to Little Mix singer Perrie Edwards, who is currently supporting Demi Lovato on her Neon Lights Tour, along with bandmates Jesy Nelson, Leigh-Anne Pinnock and Jade Thirlwall.

In a cryptic tweet posted a few hours ago, the star hinted he's dealing with some emotional issues while his 20-year-old fiancée is away.

"I'll give but if there's nothing left to give what can I do ? ?,,,,,,,,, (sic)," he posted to his followers.

Many of them responded with concerned messages, asking the star what was wrong.

While Perrie is away performing, Zayn has been keeping himself entertained with friends and family and posting pictures of his fun nights on Twitter.

It also seems he's been enjoying the odd tipple recently.

"Meet my friend ... Jack Daniels :) he's cool, ha (sic)," Zayn tweeted.

While Perrie doesn't have her own Twitter page, she's been using Little Mix's official account to keep fans updated and message her man.

"Just sat reminiscing on such a good night! I miss our crew! @jonnieedwards @katheeerine @zaynmalik Perrie