The 22-year-old former Sheffield United frontman was born in Denmark to a Danish mother and a Nigerian-French father.
He moved to England at early age and is now technically eligible to represent all four countries.
He has played for the country of his birth at Under 19 and Under 21 level and was called up for the senior team in November 2025 but was forced to withdraw due to injury.
He has been impressive for Newcastle this season and has recently been attracting the attentions of the Nigerian Football Federation.
"I'm sure [Danish head coach] Brian Riemer is handling the situation, because we must not lose William Osula," the former Danish international told BT Denmark.
"So, Riemer is aware of the importance of a young forward. If the call reveals that there are doubts in Osula's mind, then Riemer will go to fish and chips in Northeast England [to talk with Osula and convince him to play for Denmark].
"It's obviously about emphasising how bright Denmark's and Osula's future looks if he pulls the red shirt and not the green shirt over his head."
Mikel Arteta insists two major refereeing calls have gone against Arsenal at crucial moments in the title race after their crucial 1-0 win over Newcastle on Saturday.
Arsenal climbed back to the summit of the Premier League with a tense 1-0 victory over Newcastle on Saturday, edging three points clear of nearest challengers Manchester City.
Martin Odegaard has admitted Arsenal's 2-1 defeat to Manchester City last weekend was difficult to accept as the Premier League title race reaches a critical stage.
Midtjylland midfielder Alamara Djabi is in recovery after being seriously injured in a stabbing in Denmark.
