The United States could ask visa applicants to reveal the passwords to their social media accounts, as part of the Trump administration's enhanced vetting of people entering the country.
Department of Homeland Security secretary John Kelly said the measure was being considered to provide officials more information on applicants from failed nation states such as Syria and Somalia, where conflict had made record-keeping difficult.
Testifying to the US Congress Homeland Security Committee, Kelly said information provided by applicants currently isn't sufficient.
"Say we want to ask them what websites they visit and give us their passwords so that we can see what they do," Kelly said.
"If they do not want to give us that information, if they do not cooperate, then they do not come in".
Kelly also said the DHS is considering obtaining applicants' financial records to see if they're on terrorist organisations' payrolls.
Asking visa applicants to provide passwords for their social media accounts goes further than prior vetting proposals.
In June last year the DHS wanted to include social media information on the I-94 and I-94W arrival and departure forms that all visitors to the US fill in, whether they're arriving under the Visa Waiver Program or on a non-immigrant visa.
The proposal followed the Obama administration's Visa Waiver Program Improvement and Terrorist Travel Prevention Act, which was enacted in 2015, and DHS pilot programs run since 2011 to review social media activity that were never adopted as general policy.
At this stage, it is not clear if the proposal would only apply to visitors and refugees from Somalia, Syria, Iraq, Iran, Libya, Sudan and Yemen who were temporarily barred from entry to the United States, or all visitors to the country.