Billing was born in Copenhagen to a Nigerian father and a Danish mother and has already represented the European country at various youth levels.
He received his first call up to the Denmark national team last year but he is yet to earn a senior cap, meaning he is still eligible to represent Nigeria.
The former Huddersfield midfielder has confirmed he has been approached by Nigeria coach Gernot Rohr, but he has no desire of switching allegiance to the West African country.
“I think there are some rumours that come out of nowhere. When I saw it, I thought it might be good just to make a Danish article. I saw the last time people started to speculate that I didn't mind playing for Denmark and blah, blah, blah,” Billing told BT.
"It would be strange to stand up for Nigeria when I feel 100 percent Danish. Of course, I have Nigerian roots and am half Nigerian, but I was raised and born in Denmark.
“I have a Danish mother, Danish little brother and Danish little sister and a Nigerian father. But this is Denmark I want to stand for. That's my big dream.
"I've talked to the coach, but I know where I want to play. I want to play for Denmark, so it is no longer than that.
"He [Rohr] just said he really wanted me to play for Nigeria because the upcoming World Cup and Africa Cup of Nations will be played soon. I made it pretty clear to him that I wanted to play for Denmark. That's my big dream."
Billing made 27 appearances for Bournemouth in the Premier League before the 2019/2020 season was suspended because of the Coronavirus pandemic.