Journalists asked about the companies' overseas manufacturing practices on the first day of what White House aides have dubbed “Made in America Week”.
The President has vowed to increase trade regulations in an effort to protect American companies and workers.
But Mr Spicer avoided saying whether the President and Ms Trump – whose businesses rely on cheap labour in countries including Bangladesh and China – would commit to stopping manufacturing abroad.
Instead he said the President was focussing on the message that “all companies can hire here, can expand here, can manufacture here”.
Asked about the Trump family businesses, he said: “It’s not appropriate for me to stand up here and comment about a business. I believe that is a little out of bounds.”
Mr Spicer was asked to say whether legislation could be introduced to stop businesses, such as Ms Trump's, complaining that some products could not be produced in the US.
“I can’t answer that question, in the sense that I’m not — but I can tell you that it depends on the product,” Mr Spicer said.
“There are certain things that, certain industries that we don’t do as much any more, and there are certain things that we do do more .... In terms of scalability, there are certain things that we may not have the capacity to do here, in terms of having a plant or factory that can do it.”
He continued by saying the “beautiful thing about a capitalistic society” was that if there was demand for change, it would happen.
Mr Trump has already come under heavy fire for granting seasonal visas to thousands of foreign workers at the start of the “Made in America” campaign.
Advocates of stricter immigration control lambasted the move, arguing American workers should get the jobs.
Launching the drive promising to protect American companies, Mr Trump said: “We're going to stand up for our companies and maybe most importantly for our workers.
“Clearly it's time for a new policy, one defined by two simple rules: We will buy American. And we will hire American."