India, Sept. 20 -- American companies, including the biggest H-1B visa issuer Amazon.com Inc., have told employees who hold such permits to return to the US immediately, after Donald Trump ushered in the "gilded age of US immigration".

"If you have H-1B status and are in the US, stay in the country for now," the world's largest e-commerce firm told employees in a note seen by Reuters. Amazon also has recommended employees who hold H-1B and H-4 visas to return to the US before midnight of 21 September.

An immigration counsel for JPMorgan Chase & Co. has told its H-1B visa holders to remain in the US and avoid international travel until further guidance, according to an internal email.

Microsoft Corp. has also told its H-1B visa and H-4 ...