The Trump administration and U.S. airlines are clashing over how to collect and disseminate contact information for travelers entering the country as the government steps up efforts to track the coronavirus.

The dispute spilled into the open this week ahead of a White House meeting Wednesday between Vice President Mike Pence and airline executives. Last month, the Department of Health and Human Services and Centers for Disease Control and Prevention instructed carriers to divulge each traveler’s name, email and U.S. address, plus two telephone numbers.

The airlines say they often lack all five pieces of data on their customers—especially for those who purchased tickets abroad or through a third-party, or those who transferred from another airline because of interrupted travel plans. About 26% of passengers don’t have a phone number in their travel record and 44% don’t have an email, according to Airlines for America, a lobbying group.

“It’s clear to me that the government is going to require the collection of this information,” Sharon Pinkerton, senior vice president of legislative and regulatory policy at Airlines for America, said Tuesday. “It is not clear to me how they are going to require it.”

Representatives of the CDC and the health and human services department didn’t immediately respond to queries seeking comment.

‘Contact Tracing’

Another proposed change for “contact tracing” would be for airlines to ask U.S. citizens returning from abroad for an address when they return to the country. Such a requirement is spurring privacy concerns among U.S. airlines, Pinkerton said. The question is already part of what Customs and Border Protection asks foreign travelers, but no enforcement mechanism exists if the response isn’t truthful.

More broadly, the carriers have argued that the government already possesses whatever contact data is available on international travelers, Pinkerton said. That information is from the Department of Homeland Security, which maintains databases of visa applications, other authorization documents and enrollments in “trusted traveler” programs.

During weeks of meetings, government officials have pushed airlines to adjust their information systems to collect contact data. The carriers have argued that such costly changes couldn’t be made quickly. The dispute was reported Monday by the Washington Post.

The airlines have suggested that the U.S. establish a website or new mobile app to require submission of all five pieces of contact data, as Singapore and South Korea have done, Pinkerton said.

That would take “two to four weeks versus the process that the CDC would like us to engage in” of having airlines alter multiple information systems, she said.

Pence’s guests at the Wednesday meeting are expected to include American Airlines Group Inc. Chief Executive Officer Doug Parker and his counterpart at United Airlines Holdings Inc., Oscar Munoz.