Former US secretary of state Madeleine Albright has said she is ready to register as Muslim in a show of solidarity.
Ms Albright tweeted: "I was raised Catholic, became Episcopalian & found out later my family was Jewish. I stand ready to register as Muslim in #solidarity."
She added: "America must remain open to people of all faiths & backgrounds."
During his election campaign, US president Donald Trump proposed a temporary ban on foreign Muslims entering America, and at one point suggested Muslims already in the country should be required to register.
While those proposals evolved over time, Mr Trump did not explicitly take a Muslim ban off the table.
Ms Albright served under former president Bill Clinton. She did not say where or how she would register as a Muslim.