That's according to White House spokesman Michael Short, who says the signing was done privately.
The new directive aims to address legal issues with the original order, which caused confusion at airports, sparked protests around the country and was ultimately blocked by federal courts.
The revised order is narrower and specifies that a 90-day ban on people from Sudan, Syria, Iran, Libya, Somalia and Yemen does not apply to those who already have valid visas.
The White House also dropped Iraq from the list of banned countries.
In another development, Nigeria is warning citizens not to travel to the United States, saying several Nigerians with valid visas have been put on the next plane home.
Nigeria is not on the list of six Muslim-majority African nations whose citizens President Donald Trump wants to bar from entering the United States.
But the special assistant to the president on foreign affairs and the diaspora says in a statement that several Nigerians with valid multiple-entry visas have been refused entry to the United States. Abike Dabiri-Erewa (ah-BEE'-kay dah-BEE'-ree EH'-reh-wah) says their visas were canceled when they landed and they were put on the next plane home.
She advises: "Nigerians who have no compelling or urgent reason to travel to the U.S. to postpone their travel plans until the new administration's policy on immigration is clear."