The 24-year-old old singer/songwriter admits he tries to stay in regular contact with all of his 1D bandmates but Zayn - who quit the boy band in 2015 - is the most difficult to get hold of because he's always changing his phone number.
Speaking to Australia's 'Today' show, he said: ''I spoke to Zayn about three weeks ago. We had a big conversation and on text and stuff. But Zayn is the kind of fella that changes his number every five minutes. Don't know where he's at.''
Niall also gave 'Directioners' hope that the boys might get back together, with or without Zayn, by revealing that he and the other three guys, Liam Payne, Harry Styles and Louis Tomlinson, talk all the time even though they are all bust with their solo careers.
He said: ''Harry is doing his tour. Louis is making more music. Liam is down in Mexico at the minute. We are all like to keep in touch.''
Niall's comments that he has been speaking to Zayn, 25, seemingly prove that their has been an improvement in relations following his decision to walk away from the group - who were former by Simon Cowell on 'The X Factor' in 2010.
Back in 2016, Zayn claimed in an interview with Billboard magazine that he had ''reached out'' to some of his former bandmates but had never got a response.
The 'Pillowtalk' hitmaker said: ''I've reached out to a few of them and not got a reply ... Certain people have pride issues, but it's stuff you overcome in time.
Liam recently sparked 1D reunion excitement when he claimed the boys' solo careers are just a warm up for an epic comeback tour.
He said: ''It suddenly struck me that actually what we're doing right now is going to make this bigger, because we can do five concerts in one concert at a time it's going to be the most amazing thing ever!
'So I think everyone who's not enjoying the One Direction break at the moment, just know that this is like a super important time for us to be able to give you the best show ever. This is like the warm up stage - that's what it feels like to me anyway.''
His new album Underneath It All is out now.
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