Holders of business and visitor visas will be affected by the move — amounting to almost 3.6 million applicants per year, the proposal estimates.
However, travellers can choose not to disclose the information, and will still have their requests processed "without a negative interpretation or inference."
The move is meant to increase security as well as to "facilitate legitimate travel."
RELATED: Country and state borders
Country and state borders
Country and state borders
Virginia and Tennessee
The Virginia-Tennessee state line is marked between the double yellow line on State Street in downtown Bristol.
Netherlands and Belgium
Baarle-Nassau village, the Belgium/Netherlands border goes in the middle of the house.
United States and Canada
Nancy Rumery, Haskell Free Library Director straddles the U.S.- Canada border line which runs through the library's International Reading Room. The U.S. is to the right.
(Photo by Stan Grossfeld/The Boston Globe via Getty Images)
Spain and Portugal
The border between Spain and Portugal is clear because of the distinct difference in the road.
Norway and Sweden
Sign in Finnish, Swedish and Northern Sami by Snow Covered Road at Border of Norway and Finland, Klipisjarvi, Lapland, Finland.
Argentina and Brazil
Tourists view the Iguazu Falls from an observation platform at the Iguazu National Park near the southern Brazilian city of Foz do Iguacu June 21, 2014. Forming a border between Argentina and Brazil, the Iguazu Falls, South America's largest falls, attract more than 1 million visitors a year.
Poland and Slovakia
Tatra Mountains is situated on the border between Poland and Slovakia and with 25 summits above 2500 meters, the Tatras is the highest range of the Carpathian Mountains chain. The state border of Slovakia and Poland runs along the main mountain ridge, starting with Laliove sedlo and leaving the High Tatras at Rysy peak, 2499 m. Seen from far left - Kasprowy Wierch Peak, 1,987 m, with station. Kasprowy Wierch Peak also delineates the border between Poland and the Slovak Republic. Swinica Peak, 2,301 m, in the center and the Slovak Valley of Valentkova Dolina on the right.
(Jadwiga Figula via Getty Images)
United States and Mexico
'The new steel beam border fence overlooks Nogales, Mexico. Since this section of new 18 foot tall fence has been completed in 2011, officials have cut the number of aliens entering the United States at this particular location drastically. However, only 685 miles of the 2,100 miles of common border between Mexico and the US have been fenced, and much of that fence is useless barbed wire or chain link. One mile of this new fencing costs from $1 million to $3 million dollars, and Arizona is using prison labor to cut down on costs. Fences will not totally deter illegal immigration - Nogales, for instance, is reputed to have more underground tunnels for smuggling people and drugs in the US than any other location along the border.'
(chapin31 via Getty Images)
Spain and United Kingdom
Pedestrians cross the tarmac at Gibraltar International Airport in front of the Rock near the border with Spain in the British overseas territory of Gibraltar, historically claimed by Spain, June 24, 2016, after Britain voted to leave the European Union in the EU BREXIT referendum.
Pakistan and India
A huge crowd of Pakistani and Indian residents gather to watch the Pakistani and Indian border security forces perform their daily flag lowering ceremonies at the Wagah border post between the rival nations July 12, 2001. More than half a century after the hasty partition of the Asian subcontinent by departing British colonialists, relations between India and Pakistan are still dogged by hatred, suspicion and misunderstanding. Musharraf is due to visit India from July 14-16 for summit talks with Indian Prime Minister Atal Behari Vajpayee will focus the dispute territory of the Himayan region of Kashmir.
Chile and Argentina
Monument to Christ the Redeemer of the Andes, on the mountain pass marking the border between Chile and Argentina, Cumbre or Uspallata pass, Chile and Argentina.
(Photo by DeAgostini/Getty Images)
Panama and Costa Rica
Car crossing railway track bridge at Costa Rica - Panama border.
(Kryssia Campos via Getty Images)
China and Nepal
Mount Everest - also called Qomolangma Peak, Mount Sagarmatha, Chajamlungma (Limbu), Zhumulangma Peak or Mount Chomolungma - is the highest mountain on Earth, and the highest point on the Earth's continental crust, as measured by the height above sea level of its summit, 8,848 metres (29,029 ft). The mountain, which is part of the Himalaya range in Asia, is located on the border between Sagarmatha Zone, Nepal, and Tibet, China.
(hadynyah via Getty Images)
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The public has 60 days to comment on the proposal before it will be formally considered.
Popular social media websites such as Facebook are blocked in China, with the majority of Chinese citizens using social media sites such as Weibo and Renren.
A CBP spokeswoman said that travellers could submit social media information about "any platform" that they used.
The U.S. had already started scanning social media accounts last year, for people entering the country through its Visa Waiver Program. A majority of the travellers affected had been from Europe.
Customs has been reportedly demanding social media passwords at the border. Tips to stay safe: https://t.co/TjeRoSsqzo