"To date more than 250 is the number," Palladino said when asked to clarify a recent comment by US Vice President Mike Pence.
On Wednesday, Pence said the State Department will revoke another 77 visas from individuals with ties to Maduro.
Palladino noted that the 77 visa revocations mentioned by Pence are included in the more than 250 he mentioned.
The political crisis in Venezuela escalated in late January, when opposition leader Juan Guaido declared himself to be the country's interim president.
Maduro, who was sworn in for his second presidential term earlier that month, qualified Guaido's move as an attempt to stage a coup orchestrated by Washington.
The United States immediately recognized Guaido, and 54 of its allies followed suit. Russia, China, Mexico, Turkey and a number of other states have said they consider the Maduro government to be the legitimate authority in Venezuela.