U.S. President Donald Trump said on Friday he plans changes to the H-1B program that grants temporary visas for specialty occupations such as technology or medicine, but his administration said later he was referring to changes that were proposed last year.

"H1-B (sic) holders in the United States can rest assured that changes are soon coming which will bring both simplicity and certainty to your stay, including a potential path to citizenship," Trump said on Twitter. "We want to encourage talented and highly skilled people to pursue career options in the U.S."

It was unclear what Trump meant by a "potential path to citizenship" for H-1B visa holders, who already are eligible to be sponsored by employers for legal permanent residency, which would then make them eligible to become U.S. citizens.