Niall Horan
Niall Horan and Selena Gomez were said to in a relationship in late 2015. Getty

Niall Horan has been vocal about his admiration for his former girlfriend Selena Gomez in recent months. The One Direction singer had told Ryan Seacrest to help him rekindle his romance with Gomez after he shared a hug with songstress at the 2016 American Music Awards in November.

Now, it seems like Horan has taken the first step towards reigniting his romance with Gomez as the former said he was "missing" the songstress on Instagram on 9 January.

"Miss you guys. Can't wait to see you all," the 23-year-old wrote on a 2015 photo of Gomez. (Via HollywoodLife)

As soon as Horan made the comment on the photo, fans of the two stars have started to speculate whether they are a couple.

But when Horan praised Gomez for her candid speech at the 2016 American Music, a source had told HollywoodLife that although she was "flattered" by his kind words, she does not want to get involved in serious relationships as part of her recovery from "mental health" issues.

"Selena is flattered by what Niall had to say to Ryan [Seacrest], but part of her recovery involves no serious relationships," a source told the gossip site. "In fact, for the time being she's been advised not to date. Plus, dating is pretty much the last thing on her mind now. She is focused on herself and spending time with close friends."

Gomez and Horan were linked in late 2015. However, in February 2016, Gomez confirmed she was single.

"The reason why everything cooled was because [Selena Gomez] didn't want to take anything further. Niall really was happy when they hooked up but now realizes it was a drunk hookup night that didn't do anything more because Selena didn't want it," a source told Hollywood Life at the time.

"[Niall Horan] would have liked it to have been something but now that time has passed he realizes a relationship with Selena will never happen. And being her friend is an OK landing spot."