The review covers people who travelled to the US on tourist and business visas and later sought to remain in the country through asylum applications or other routes to permanent status.
The US State Department has not officially confirmed the reported figure.
Could Indians face scrutiny?
Asked by NDTV whether Indian nationals could also be caught up in the review, State Department spokesperson Tommy Pigott said a US visa is "not a right, but a privilege."
Pigott said the Donald Trump administration is stepping up efforts to tackle "fraud and abuse" in the US visa system.
However, US officials have not indicated that Indian applicants are being singled out for additional scrutiny or provided any specific figure for Indians whose visas may be under review.
What is the US looking for?
The State Department, working with the Department of Homeland Security, is examining cases in which people entered the US on temporary visas but later attempted to remain permanently.
The central question is whether the person had already planned to stay in the US when applying for the temporary visa but concealed that intention from consular officials.
Pigott stressed that temporary visas are issued with the expectation that the holder will eventually return to their home country.
"If an individual lies to a consular officer about their true intentions, that can constitute fraud and may result in the revocation of their visa," he told NDTV.
Applying for asylum doesn't automatically mean fraud
Officials have made clear that simply applying for asylum after entering the US on a temporary visa does not automatically amount to visa fraud.
Instead, investigators are focusing on the person's intentions and the timing of their actions.
The review seeks to determine whether someone had already decided to remain permanently in the US before their visa interview and deliberately concealed that plan while applying for a temporary visa.
Review to expand in phases
The State Department has not disclosed the final number of visas that could be affected. An official said the review is still underway and that the figures "could change" as the process progresses.
The scrutiny is expected to be carried out in phases, rather than through a single sweeping action.
What it means for US visa holders
The review is part of the Trump administration's broader tightening of immigration enforcement since the president returned to the White House for a second term.
For current visa holders, the message from US officials is clear: holding a visa does not guarantee an indefinite right to remain in the country.
If authorities determine that a person deliberately misrepresented their intentions when obtaining the visa, the visa could potentially be revoked, even if the individual has already spent considerable time in the US.