The development comes after RSAF and Defence Science and Technology Agency (DSTA) completed a technical evaluation to select the next-generation fighter.
The existing fleet of F-16s have been in service since 1998 and are set to retire soon after 2030.
Following the five-year evaluation, the F-35 was deemed to be the most suitable replacement.
The F-35 defeated competition from rival European and Chinese models.
In a statement, the Singapore Ministry of Defence (Mindef) said: “The technical evaluation also concluded that the RSAF should first purchase a small number of F-35 JSFs for a full evaluation of their capabilities and suitability before deciding on a full fleet.”
In the next phase, Mindef will begin negotiations with relevant parties in the US before arriving at the formal decision to buy the F-35 JSF.
The ministry has not clarified the exact quantity or variants of the F-35 JSF that are expected to be acquired.
The F-35 Lightning II is a fifth-generation advanced stealth fighter aircraft with speed, agility, fully fused sensor information, network-enabled operations and advanced sustainment. It enables pilots to avoid detection by radars.
Lockheed develops the F-35 in collaboration with partners Northrop Grumman and BAE Systems, which respectively build the centre and aft fuselages.
A Lockheed Martin spokesperson was quoted by Reuters as saying: “We look forward to supporting them on their continued evaluation of the F-35.”