John Kirby said other countries' choices were sovereign and respected by the USA, but had no bearing on the White House's decisions.
"It doesn't change our calculus with regards to F16s," Kirby told reporters, explaining that the Polish move "does not affect, does not change" that.
Kirby also praised Poland for "punching above its weight" in its support of Ukraine in its war with Russia.
"They've provided a significant amount of security assistance, right along with the other more than 50 nations that that have come together," he said.
"As with every other contribution by every other nation, they get to determine not only what they're going to give, but how they're going to characterize it," Kirby continued, adding: "an announcement by another nation to provide fighter aircraft ... does not change our own sovereign decision-making, about, in this case, F-16s."
The Security Council spokesman cautioned that sending fighter jets would not be the best use of US resources.
Asked whether Poland's President Duda and US President Joe Biden had consulted over Warsaw's MiG-29 decision, Kirby replied he was not aware whether such a conversation took place. (PAP)