Musk, the world's richest person and President Donald Trump's biggest donor, had originally given federal government employees until the end of Monday to explain their work achievements in an email.
"Over the last 16 months, Israel has dealt a mighty blow to Iran's terror axis. Under the strong leadership of President (Donald) Trump and with your unflinching support, I have no doubt that we can and will finish the job," Netanyahu said.
The move comes as President Donald Trump has sought a return to a strict binary definition of gender in the United States, leading attacks on transgender people and issuing an executive order that states the country only has two genders -- male and female.