Davis, 17, became the first Singaporean footballer to sign a professional contract with a Premier League club.
However, following his application to defer from compulsory military service - submitted by his father - authorities said he did not meet the requirements.
In Singapore, men over 18 must serve for two years in either the armed forces, police or civil defence force to meet the requirements.
Davis's father, Harvey, has appealed the defence ministry's (MINDEF) decision. But MINDEF released a statement on Wednesday saying that Davis has no intention of doing his national service and that his actions only served to "further his own professional career, not national interest".
Davis Snr. has fired back and said his son will likely serve his military service, but only if he doesn't get a contract renewal at Fulham or a deal elsewhere when his finishes in 2020.
"There are a lot of variables all dependent on his development and progression, and anyone who understands how professional football and sports works will understand this," Mr. Davis told the BBC.
"In my discussions with SportSG and the Ministry of Culture, Community and Youth (MCCY), I was clear that Ben should do his NS but the question is just when.
"This point was reiterated in an email response which was sent to MCCY on May 15. In that email, I had said very clearly that while renunciation was an option, it is not Ben’s intention at all as he would like to represent Singapore.
"My older boy has already completed his NS, and both Ben and his younger brother Jai will also complete their NS. The only question is timing for Ben, as we would like to give him the best opportunity to play at the highest possible professional level in the UK and Europe.
"If Ben doesn't get a renewed contract or new contract by May 2020 then he should return to serve his NS."
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